Like the Google Talk badge, site visitors can send your private messages via the Yahoo! Messenger Pingbox chat box without using their own IM client.
IM Tutorial: Learn how to create an IM bot for Google Talk, Yahoo! Messenger, AOL AIM and other instant messaging clients.
The newfound bonhomie between Yahoo & Google is not just about AdSense, the two companies are connecting their popular IM clients as well.
AirTalkr is an Instant Messenger that connects to MSN (windows live), Yahoo!, Google Talk, AOL (AIM) and ICQ. AirTalkr can run on Windows and Mac.
Call your gtalk or Google Talk friends from Yahoo! Messenger or the new MSN / Windows Live Messenger. You can also make phone calls to traditional landline numbers just like Skype.