Gmail Skins for FF Users

Gmailskins adds the following features:

1. Change the colour/skin of your inbox.
2. Integrate your google homepage alongside your inbox. This allows you to view weather reports, rss feeds, news headlines, flickr recently added, google calendar module etc from your inbox.
3. Easily insert images from your Picasa web album in to your emails
4. Insert smileys/emoticons and images in to your emails.
5. Insert HTML tables and other complex HTML in to your emails.
6. Make the navigation (Inbox, Starred, Sent Mail, etc) horizontal.
7. Fix the navigation in place so that you don't have to scroll to the top of the page to see it.
8. Zebra stripes on mailbox - pretty!
9. Change the attachment paperclip (on inbox) to an icon indicating the type of attachment.
10. Hide various page elements (invite panel, page footer, your email address from the top right of inbox).

http://gmailskins.mozdev.org/