Trillian

Trillian is an instant messaging application for windows that can connect to multiple IM programs such as AIM, ICQ, MSN, Yahoo!, IRC, Novell GroupWise, Bonjour, Jabber and Skype (the latter four with Trillian Pro, which allows for additional plug-ins). The software is named after a fictional character in The Hitchhikers Guide to the Galazy' by Douglas Adams.