[Osiris]

A good way to test Firefox 3 without having to install it over your precious Firefox 2 client is to download and run the Firefox 3 portable version which comes with all features of Firefox 3 but does not tamper with previous versions of Firefox in any way. The portable client uses its own profile which is located in the same directory structure as the program’s files.
It pretty much does everything that Firefox 3 can do as well. It is possible to install extensions and themes for instance. Bookmarks can best be imported into the portable version. Just point it to your bookmarks.html file in your Firefox 2 profile folder.
It is even possible to run both the Firefox 3 portable version and another Firefox version at the same time. To do that you need to create another profile for the portable version. Head over to my article that explains how to multiple Firefox profiles simultaneously.

Firefox 3 Final Portable

[Trotter]

Just what I was looking for. I am going to slap this puppy on a flash drive to use at work.

[ezysk]

Well listen, if anyone has the Firefox 2.0 version, just let me know, cuz Version 3.0 just aint worth didly squat.

[Trotter]

Try oldversion.com for FF2. Sorry to hear you are having problems with 3... it runs great on my end.

[Mak213]

Originally Posted by ezysk

Well listen, if anyone has the Firefox 2.0 version, just let me know, cuz Version 3.0 just aint worth didly squat.

Hello,

Check yoru thread. As i have given you the best known solution to solve your issue.

Cheers,
Mak

[zedman3d]

Mozilla Firefox, Portable Edition | PortableApps.com - Portable software for USB drives

Theres the portableapps.com link.