I've been running my different versions of Firefox under different profiles, that way I can keep each instance unique. This works great, but I still couldn't figure out how to open both Firefox 2 & 3 at the same time. Turns out I was missing the -no-remote command line parameter in my Firefox 3 shortcut.
Here's a great write up on how to run Firefox 2 and Firefox 3 simultaneously—which provides you with full instructions on setting your shortcuts up so you can run Firefox 2 & 3 at the same time.
Comments for this entry have been disabled.