[joeshaw]

I use this Greasemonkey script to do this. It works in Chrome and Firefox:

http://userscripts.org/scripts/show/24430

It does the unread count thing, but it also toggles between it and the chat icon if you have unread chat messages. It's a must if you pin gmail tabs.

[brownleej]

I've been using this script all day, and it's been great. Thank you so much.