Although it's possible to create separate login profiles on both Windows and Linux, it's often inconvenient when sharing a computer with other household members to start a whole new login session when someone just wants to quickly access their webmail or homepage. A more convenient solution is to create separate user profiles in Firefox to manage different homepages, bookmarks, etc.

Firefox's built in profile manager makes creating new user profiles a trivial task. In this example, I'm going to create two new profiles; His and Hers. I'm doing this in Xubuntu 8.04. The Firefox commands should be the same in other versions of Linux or even Windows, but the procedure to create the desktop launchers may vary slightly depending on your desktop environment.

The first step is to open a terminal and type:
firefox -ProfileManager

With the release of Hardy Heron it is possible to use the 64bit browser. Flash with the nspluginwrapper, the java Openjdk and Mplayer plugins are in the Ubuntu repositories. If you need support for more plugins and would like to install a 32bit version of firefox to accomplish that, then see the section below. If you want to keep using your 64bit browser and just need flash, then see the nspluginwrapper section further down in this page which will allow you to run your 64bit browser and 32bit flash.

best tools available and quickly describing how to activate/install/use them.

Use tamperdata to view and modify HTTP/HTTPS headers and post parameters.
Trace and time http response/requests. Security test web applications by modifying POST parameters.