Copied from Majorgeeks:
Portable Firefox is a fully functional package of Firefox optimized for use on a USB key drive. It
has some specially-selected optimizations to make it perform faster and extend the life of your USB
key as well as a specialized launcher that will allow most of your favorite extensions to work as
you switch computers. 
It will also work from a CDRW drive  in packet mode , ZIP drives, external hard drives, some MP3
players, flash RAM cards and more.
This is an unofficial package. It is an official build, but has been modified and a specialized
launcher added to make extensions portable. 
No warranty is expressed or implied.
To install, just download the ZIP and unzip it to the root directory of your USB drive. It will
create a  firefox  directory and all the requisite directories underneath. To use Firefox on your
drive, launch it with the PortableFirefox.exe file in the firefox directory. DO NOT launch the
firefox.exe file directly, as this will create a profile on your hard drive or use an existing one.

Additionally, be sure you ve closed any local copies of Firefox and that they ve finished shutting
down. Otherwise, a new window of your local install will be launched. This is a feature of Firefox
itself to prevent multiple copies running at the same time. 
Copied from Mozilla Firefox Homepage:
Personal
Library
Make your browser as efficient as you can imagine. Your browsing history  all the websites you   ve
seen  and your bookmarks  all the websites you   ve saved  are archived in the Library, where they
can be easily searched and organized. You can also save your frequent searches in dynamic smart
folders that automatically update as your bookmark list and history grow.
Tags
Label a site with names or categories that are meaningful to you. For example, you can label the
site www.bbc.co.uk with the    news    tag as well as the    foreign investments    tag, plus give
www.nytimes.com the    news    tag, too. When you enter    news    into the location bar, both
sites
will be shown as results. A single site can have multiple tags, and there   s no limit to the
number
of tags you can create. You may not remember the exact name of a site, but with a tag, you   ll be
able to find it in a way that makes sense to you.
Smart Location Bar
A quick way to get to the sites you love   even the ones with addresses you only vaguely remember.
The new Firefox 3 location bar learns as you use it   it   s so highly evolved that we like to call
it the    Awesome Bar   . Over time, it adapts to your preferences and offers better fitting
matches. Type in a term and the autocomplete function includes possible matching sites from your
browsing history, as well as sites you   ve bookmarked and tagged in a drop down. For example, you
could enter the tag:    investments    to find    www.fool.com   . Matched terms are highlighted,
making the list of results easy to scan. 
One-Click Bookmarking
Manage your bookmarks a lot or a little. One click on the star icon at the end of the location bar
bookmarks a site. Two clicks and you can choose where to save it and whether to tag it. File
bookmarked sites in easy-to-access folders and organize according to theme  like    job search   
or
   favorite shopping    . Find your bookmarked sites in a flash by entering the tag, page or
bookmark name into the location bar. The more you use your tags and bookmark names in the location
bar, the more the system will adapt to your preferences.
Smart Bookmark Folders
These dynamic folders give you easy access to your favorite sites and can be placed in your
Bookmarks menu or Bookmarks toolbar. We   ve included some for you as defaults, including one that
shows you the sites you visit most frequently  create your own by saving your searches in the
Library .
Security   Privacy
Instant Web Site ID
Want to be extra sure about a site   s legitimacy before you make a purchase? Click on a site
favicon for an instant identity overview. Another click digs deeper: how many times have you
visited? Are your passwords saved? Check up on suspicious sites, avoid Web forgeries and make sure
a
site is what it claims to be.
Anti-Malware
Firefox 3 protects you from viruses, worms, trojan horses and spyware. If you accidentally access
an attack site, you   ll receive a full-sized browser message as a warning. A continuously updated
list of attack-sites tells us when to stop you from browsing, so there   s nothing for you to
update
or maintain.
Anti-Phishing
Shop and do business safely on the Internet. Firefox gets a fresh update of web forgery sites 48
times in a day, so if you try to visit a fraudulent site that   s pretending to be a site you trust

like your bank , a browser message   big as life   will stop you.
Parental Controls
Enforce parental control settings you   ve entered on Windows Vista with Firefox 3   stop unwanted
downloads and more. Firefox   s intuitive design keeps you from second-guessing your setup.
Anti-Virus Software
Firefox 3 integrates elegantly with your antivirus software. When you download a file, your
computer   s antivirus program automatically checks it to protect you against viruses and other
malware, which could otherwise attack your computer. [available in Windows only]
Add-ons
Firefox looks for a secure connection before installing or updating add-ons, 3rd party software,
and Personas.
Password Manager
We   ve seamlessly integrated this feature into your surfing experience. Choose to    remember   
site passwords without intrusive pop-ups. Now you   ll see the    remember password    notification
integrated into your view at the top of the site page.
Clear Private Data
Clear your private data automatically   with just one click or a keyboard shortcut. Your info is
gone for good   on your own computer or the one at your local library. It   s that easy.
Customized Security Settings
Control the level of scrutiny you   d like Firefox to give a site and enter exceptions   sites that
don   t need the third degree. Customize settings for passwords, cookies, loading images and
installing add-ons for a fully empowered Web experience.
Automated Update
Our open-source security strategy lets us find   and fix   security issues in record time, making
Firefox the safest way to surf. Install upgrades when you receive automatic notification or wait
until you   re ready.
Pop-Up Blocker
Banish pop-ups  and pop-under windows  from your surfing experience once and for all. Or, find a
happy medium   choose to view blocked pop-ups or create an    allow    list of sites whose pop-ups
you   re okay with seeing.
Customization
Add-ons Manager
You can now find and install add-ons directly in your browser. You no longer need to visit the
add-ons Web site, simply fire up the new Add-ons Manager. Not sure which add-on is right for you?
Ratings, recommendations, descriptions and pictures of the add-ons in action help you make your
selection. The fully integrated Add-ons Manager even lets you view, manage and disable third-party
add-ons in a few easy clicks.
Over 5,000 ways to customize
The sky   s the limit with a growing library of over 5,000 Firefox Add-ons, little extras you
choose to download and install for a browser that works your way. Manage online auctions, upload
digital photos, see the weather forecast in a glance and listen to music all from the convenience
of
your browser. There   s no need to open a new window or tab for each task. Discover add-ons that
help you streamline coding and Web development, like Firebug, which lets you look deep into the
structure of a web page.
Browser Look   Feel
Dress up your browser as you like it. With themes, choose a darkened control panel reminiscent of a
space ship, faux wood paneling, or hundreds of other unique looks to surround your surfing. With
Personas, add a simple, lightweight    skin    to your 
browser in an instant.  Personas is a Mozilla Labs project. 
Beyond Add-ons
Add-ons are the cornerstone of customization, but adapting Firefox to suit your style doesn   t
stop there. You can add new search engines, change toolbar preferences, display different sizes,
shapes and styles for your browser   s navigation buttons and more. With additional preferences,
you
can specify a Web mail client, such as Gmail, to open up when you click on an address from a Web
page or set up a news reader application for the blogs you encounter.
Productivity
Platform-Native Look   Feel
The new Firefox looks and feels like home. Think of it as a Firefox who   s really good at making
friends. Whether you use Windows Vista, Windows XP, Mac or Linux, the browser seamlessly integrates
into your computer   s environment. A native look makes for a flawless interface that never gives
you pause.
Feed Reader
You can read feeds using an online Web service, a client-side feed reader or by creating a Firefox
Live Bookmark. So there   s no need to comb the Web for the latest news and updates. See the latest
headlines in the toolbar or menu and go directly to the articles that catch your eye.
Download Manager
An all new manager lets you download seamlessly, with even greater security. A pause and resume
feature means there   s no need to wait for a download to finish before you disconnect. So, if you 

re halfway through the latest White Stripes album and it   s time to catch the bus, just pause and
pick up downloading when you get home. The resume function also works if your system crashes or is
forced to restart. The manager shows your download progress and lets you search your files by name
or the Web address where the download came from.
Spell Checking
A built-in spell checker lets you enter text directly into Web pages    like blog posts and
Web-based email   without worrying about typos and misspellings. Work directly with the Web and
save
yourself a step.
Session Restore
If Firefox unexpectedly closes, you don   t have to spend time recovering data or retracing your
steps through the Web. If you   re in the middle of typing an email, you   ll pick up where you
left
off, even down to the last word you typed. Session Restore instantly brings back your windows and
tabs, restoring text you entered and any in-progress downloads. Restart the browser without losing
your place after you install an add-on or software update.
Full Zoom
Visit your favorite news page and read the caption under the picture   or view the picture itself
in a size you can see. An elegant new zoom feature lets you swoop in and see entire web pages. They
scale in the way you   d expect them to, with all the elements of a page   s layout expanding
equally, so you can zero in on what matters.
Image Loading
If you want to save time and bandwidth, view a site without images. Firefox will remember your
setting the next time you view the page.
Search
Smart Keywords
Search the Web in record time with smart keywords. With a few clicks you can assign keywords to
search engines, and then simply enter your key and search words in the location bar. With this
feature, typing    book home building    can search Amazon.com, and take you right to books about
home building without ever pausing at the homepage.
Search Suggestions
Start typing in the search bar and it will prompt you with a drop down of filled-in suggestions,
plus you can use the search bar as a calculator, converter and more.
Integrated Web Search
Searching the Web is a breeze with the search box inline, just to the right of your location bar.
Use the web engine of your choice to search by typing directly into the box. The width is
adjustable
so you can make it bigger if you need more space.
Hundreds of Search Engines
Access your favorite search engines quickly from the integrated search bar. You can use a new
engine for each search, or stick to your favorite. Choose from a preset dropdown list of engines or
select    manage search engines    from the same list to browse search engine options offered as
add-ons. Check out your choices now.
Find
The find feature appears in a keystroke. Search for a word or phrase on an open Web page. Highlight
text before using the feature and finder opens pre-filled with your selection. See all instances of
your search at once, or scroll backwards and forwards through the appearances of the word on the
page.
Tabs
Save on Exit
Now when you open Firefox, your tabs and windows look just like they did when you closed it down.
No need to reopen all your windows each time you start a session.
Tabs
At first glance, they look like little labels living above the site you   re currently visiting.
But they are a brilliant way to browse multiple sites at once. Simple and easy, you can think of
them as the electronic version of a well kept filing cabinet, with the tabs as the dividers and the
sites as the content kept in folders. Each new site appears as a new tab  not a new window  and can
be accessed in one click.
Reopen Closed Tabs
If you accidentally close a tab, you can reopen it in one click. Just view Recently Closed Tabs in
the History menu and select the tab you   d like to reopen.
Drag   Reorder Tabs
Get your sites in order. Simply arrange the order of your tabs by dragging them in one swift move
of your mouse.
Smooth Scrolling
Like to have all 20 of your favorite pages open at once? An elegant new feature lets you scroll
through tabs easily to see them all and access the one you want quickly.
Universal Access
Universal Customization
Go beyond translation and experience the web in a way that makes sense to you. Local developers who
know what   s best for their community have customized your Firefox browsing experience with local
dictionaries, search providers, live bookmarks and Web feeds. Depending on where you live, you   ll
see things like BBC headlines tailored to your region or experience features that work with Baidu,
the Chinese search engine.
The Language of Firefox
Firefox speaks your language like no other browser on earth. Because the Web is a worldwide
resource and we believe that resource belongs to the people, we   ve made our browser available in
as many local languages as possible. We have over 40 different translations, from French and
Chinese
to Finnish and Czech. Find your language.
Emphasis on Accessibility
By minimizing keystrokes, allowing users to zoom in on Web pages and supporting screen readers,
Firefox is that much easier to use for those with mobility disabilities and visual impairments.
Improved Text Rendering
Read your language as it   s written   more like real life. With a new graphics engine, Arabic,
Persian, Punjabi and other script languages now render in a remarkably seamless way.
Performance
Improved Memory Management
With all new management functions in place, Firefox 3 keeps memory usage under control. The XPCOM
cycle collector continuously cleans up unused memory. Plus, hundreds of memory leaks are now
remedied.
Faster JavaScript
Firefox now empowers even greater Web development, with JavaScript 1.8   including expression
closures, generator expression and array reduce. 
Smaller Memory Footprint
Short and sweet, Firefox now uses less of your computer   s memory while it   s running.
Faster Page Load
A redesigned page rendering and layout engine means you see Web pages faster   and in the way they
were meant to be seen.
Graphics Engine Improvements
Improved text rendering is just the beginning of the benefits of an all new graphic engine for
Firefox 3.
Standards
Advanced Graphics
You have to see it to believe it. The rendering of text and graphics, including SVG and Canvas, is
faster, sharper and more true-to-life than ever before, thanks to our new graphics engine.
Online Application Support
Expand the power of Web-based applications. In the past you   d click on an email address in a Web
site and your computer   s default email application would open up to send a message to the linked
address   even if you never email through the program. Now you can choose a Web mail clients  like
Hotmail, Gmail or Yahoo  Mail  to launch when you click on that email address.
Support for Advanced Web Technologies
Brand new and enhanced functionalities enable Web site authors and developers to create advanced
content and applications. Support is now available for CSS, ACID2, MathML, ECMAScript 4, Animated
Portable Network Graphics  APNG  and Microformats, to name a few. See the full list of supported
technologies.
Color Profile Support
Photographers and photo fans, your view of the Web from Firefox just gets better. You can choose to
enable top-of-the-line image display which uses technical data, like the amount of light available
and relevant distance information, to render images in an amazing new way.
Offline Browsing
Take your computer offline and still have information at your fingertips. Certain enabled sites may
allow applications   like your Web-based email   to stay with you at all times. Many sites are not
yet configured to work with this feature. Learn more about what works and what doesn   t.
Help
Live Support
We have Firefox experts waiting on stand-by to help you with questions that simply demand a live
person and a real conversation. Now you can chat with knowledgeable Firefox community members who
troubleshoot via our live chat site. You won   t be put on hold or have to wait for a response  
solve your problem on the spot.
Firefox Support
Help is right where you would expect it, as well as a few places you might not. A link at the top
of your browser takes you to a support site with the answers you   ll need. Want to dig deeper   or
have a really tough question?
Firefox   s support website has a searchable knowledge base of articles, plus forums and tutorials
full of solutions and tips for a better experience.
Changelog:
Firefox 3.0.6 is a regular security and stability update to Firefox 3.0.x.