FireFox for WEB developement
WebDeveloper is an extremely useful FF extensions that help with WEB pages design, reverse engineering and specifically with testing CSS.

My favorite feature: you can get click on any item on the screen and see all CSS styling that influence its apperance (CSS->View Style Information)

You can hide the toolbar if you happen to use FF just for browsing.
- posted by Damian @ 7:27 AM | permalink