Besides IM+ All-in-One Mobile Messenger mentioned by Temoore SHAPE Services
has one more application called IM+ for Skype
It is a fully mobile application for text communication with other Skype users and cost-effective calling to landlines and mobiles.
IM+ is also useful. You can chat within AIM / iChat, MSN / Windows Live Messenger, Yahoo!, ICQ, Jabber, Google Talk and MySpaceIM with no cost per message. IM+ All-in-One Mobile Messenger