instant messangerGoogle Talk, Google's instant messaging service ranks at the bottom of the overall ranking, which is dominated by MSN Messenger/Windows Live Messenger according to ComScore Media Metrix.

MSN Messenger/Windows Live Messenger tops with 204m subscribers, Yahoo! Messenger is second at 78m, AIM boasts of 34m users and ICQ claims 33.9m users. Google Talk claimed 3.4 million users last May. via SVS

Interestingly they also found E-buddy (formerly known as E-messenger) leads the unified messenger category, ahead of Trillian.