I tried out Firefox, and quite liked it. However, there was one thing that was really bugging me out: The "backspace" key won't let you go back one page in your history -- a pretty standard key configuration (the Windows version of Firefox does this, and so do other mac browsers). During a slow day at work, I found something to fix that problem; a plugin called keyconfig available at the Mozdev extension site.
After installing and restarting Firefox, you can access the plugin via Tools -> keyconfig. Find the entry for "back," click on it, select the data entry field and hit "backspace." The change will take effect in new windows, so you need to close the active window and open up a new one.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050111124142738