Here's a simple extension for Chrome Im working on called Tab Marker that came about because of a question on StackOverflow....
http://stackoverflow.com/questions/6566 ... gle-chrome...Ill stick it in the extension gallery when Ive done the options page and done some better icons (I HATE doing icons

).
Simply, it lets you change the favicon of the tab your currently viewing.
So far its just a popup that lets you pick from some predefined icons.
In the future Ill add an options page to pick which icons show in the popup, reorder the icons in the popup and add your own images.
Sorry its so ugly but Im still crap at css/html ;P
CRX Mime type doesnt seem to be set for the forum, so after its downloaded drag the download tab into the window to install it.
It doesnt work on the tab it was installed from until you have refreshed the page....wierd?