Adium is a free online instant messenger application which supports multiple messengers at ta time. This allows you to connect to Yahoo, Jabber, AIM, MSN and many more IM services at the same time.

Supported services:
· AOL Instant Messenger (Including ICQ and .Mac)
· Jabber (Including Google Talk and LiveJournal)
· MSN Messenger
· Yahoo! Messenger (Including Yahoo! Japan)
· Bonjour (Compatible with iChat)
· Gadu-Gadu
· Novell Groupwise
· QQ
· Lotus Sametime

Features of Adium :
GroupWise, Napster, and Gadu-Gadu
· Unlimited accounts, as many names on as many services as you want
· Draggable tabs; any number of tabs in any number of windows
· Highly customizable, yet very intuitive preferences
· Address book integration
· iTunes and other Applescript substitution
· Buddy icons in AIM, MSN, and Yahoo
· The beginnings of file transfer support for AIM, Yahoo, MSN, and Jabber and much, much more.