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 an encrypted connection (HTTPS)
• Move the inbox count to the top of the sidebar lists
• Add neat row highlights on mouseover
• Show appropriate icons for email attachments
• Filter assistant to help create filters quickly
• Message details shown automatically with each message if you like
• Reply above the item you’re replying to
• Full html signatures, including colors and rich text
• Show BCC, CC by hot key or automatically when opening Compose Mail
• A hierarchical folder system based on the label system (really saves space and organizes the labels box)
• The ability to hide chat, ihe invitation box and spam count
• Select three different skins, or none (try the snazzy Redesigned number)
• Advanced stuff if you want to write some macros

Several of these, especially HTML signatures, have been long needed in Gmail, and this is a painless way to get them.  Remember, though, that it is a Firefox add-on (extension), and will only be available on machines that have it installed along with Firefox.  If you want it whenever you need it, you will have to make sure it’s installed on all the computers you normally use.  Fortunately, it’s as easy to install as any other Fx extension.Check it out.