fring – Make free mobile calls, IM with Skype, MSN Messenger, ICQ, Google Talk™, SIP & Twitter, AIM® & Yahoo!™
it is a free beta download for mobiles - Symbian 8 or 9, Windows Mobile 5 or 6 and UIQ handsets which are accepted for that IM application. It can runs Skype(i know you dont need that.
), MSN Messenger, Google Talk, ICQ, SIP, Twitter, Yahoo! and AIM on your mobile.