gmail

If you use Gmail in the “new version” you should take a good look at Better Gmail 2, an interface package put together with Greasemonkey user scripts by Gina Trapani.  Originally available on Lifehacker, it is now an official Mozilla extension for Firefox 3.
Better Gmail 2 offers a number of enhancements, including

Force Gmail to make [...]

I think someone has taken over my Gmail account and has changed the password. What can I do? –Lloyd
It’s possible that someone has “hijacked” your Gmail account and could end up using it for anything from a prank, sending out spam, or the worst case scenario: to steal your identity.
Identity thieves have figured out that [...]

Gnomie Michael N. writes:
While https://gmail.com allows for a secure login, it even redirects for to https://mail.google.com/mail/ logon by default! Check it out.
You log on securely and immediately get sent back to unsecure email browsing and sending. There is a way to maintain a secure connection for all things with Google. What you have to do is:
Go to https://mail.google.com. [...]

Better Gmail is a compilation of the best Greasemonkey enhancements for the new Gmail interface, compiled into one extension. Enhances the new Gmail interface with Greasemonkey user scripts.
Only compatible with the new Gmail interface. Released with Compose in Gmail, Attachment Icons, Macros, Inbox Count First, Force Encrypted Connection, and Show Message Details.
[34.6K] [Win2k/XP + [...]