If you're wondering how to get Firefox 3.5 here is what to do:
1. Get Firefox 3.5
Download it from http://www.mozilla.com/en-US/products/download.html?product=firefox-3.5&os=linux&lang=en-US
and extract it to a directory of your choosing. I used /home/yourusername/ for mine.
2. Create shortcuts
First, know what your directory is, for me it is /home/mike/ and the firefox folder is named firefox and inside the folder is the program.
Than, go to your desktop and delete the old firefox shortcut (optional) and right-click and scroll over 'Create New'. You will see a bunch of choices, click 'Link To Application' and type in the first box, firefox. Then, click on the icon next to the box and scroll down until you see the firefox icon and click it, then ok. Now go to the tab, 'Application' and type in 'Description' Firefox 3.5 and then in the box 'Command' type your directory to the program. Here is an example using mine: /home/mike/firefox/firefox
Now, if you want a Taskbar link, remove the first one by right clicking the Firefox icon and clicking Remove Firefox Button. Than, click on the arrow just right of the taskbar, and go to Panel Menu, Add Application to Panel, Non-KDE Application. Type in the first box, Firefox. Then, click on the icon next to the box and scroll down until you see the Firefox icon and click it, then ok. Now fill in the Description and leave Executable blank. Go to where it says, Command Line Arguments and put in your firefox directory.
Now you have Firefox 3.5 with two easy access links. I know you're not really installing it but it still works as if you have.