Firefox with Greasemonkey: The Gmail Unread Message Count in Favicon Greasemonkey user script displays your unread message count on the Gmail site favicon. If you're not familiar with the concept of the favicon, it's the small icon that appears next to the address bar or in the tab and helps identify which sites are open in which tab (like the little 'lh' that Lifehacker uses as its favicon). With this script installed, the favicon gets even more useful by showing your unread count in addition to identifying which tab holds your Gmail account. The unread number glows brighter with each new message you receive, and it maxes out at 10. The improved favicon is a perfect compliment to the previously mentioned FaviconizeTab extension, which strips all the text from tabs so all you're left with is the favicon, but I also wouldn't be surprised to see this incorporated in Better Gmail sometime in the future (it's very similar to the already included Show Inbox Count First script). It's a simple little script, but it's a brilliant tweak. Gmail Unread Message Count in Favicon is a free download, requires Firefox and the Greasemonkey extension.