Typically I have 3 different browser windows open each with their own batch of tabs:

1. Personal browser including mail, calendar, rss feeds etc.
2. Work Browser including work wiki’s, blogs, project management tools, documentation, java applets, applications, etc
3. Utility browser which has blog posts to read, videos to watch, links emailed to me etc. Basically anything that doesn’t belong to the other two.

The problem with this setup is that instability on any of the browser windows affects them all, causing lost work or time reloading the relevant pages.

Luckily there’s a solution to this. Firefox has the concept of user profiles which were designed for multiple users on the same machine (family/shared computers etc). You need to create multiple profiles. To get the profile manager running run this from a command line:

"C:Program FilesMozilla Firefoxfirefox.exe" --profilemanager

Once the manager starts up you can create yourself a couple of different profiles.
Then create shortcuts for each of your profiles on your desktop that look like this:

Target = "C:Program FilesMozilla Firefoxfirefox.exe" --P Google -no-remote
Target = "C:Program FilesMozilla Firefoxfirefox.exe" --P Default -no-remote

Start FF with those shortcuts and you’ll have two completely separate windows. Now if one of the Windows is misbehaving you can kill it and not worry about the other one. Cool.

More info about the FF command line params can be found here.