Firefox & Gmail

If you dont like firefox, you can stop reading this post.

If you use Greasemonkey, an extension for Firefox that allows cool enhanced scripting. I think you will find some really useful scripts for gmail in googles code section. http://code.google.com/p/gmail-greasemonkey/

[Suggested by joy rahman]

Also checkout
[1] Gmail Insert HTML Signature
This script enables you to enter mail signature in HTML Format in GMAIL.
http://userscripts.org/scripts/show/6356

[2] Gmail Filter Assistant v0.16
Add an embedded filter management module in message display page, which makes adding a filter much easier.
http://userscripts.org/scripts/show/7997

[3] Gmail Signature Float
Moves your signature in Gmail to the top of the message rather than the bottom when replying or forwarding an old message.
http://userscripts.org/scripts/show/3067

check out for more at http://userscripts.org/scripts/search?q= gmail

Have fun :)
Bye