imo.im keeps an absurd number of chats connected, so that you only have to log into one place to keep your msn/skype/facebook/gtalk/etc open.
IMO Messenger - Video Calls | Video Chat - Silvercrib
Another Messenger App For iPhone: imo messenger
Stickers for IMO Messenger
Origami set for IMO Messenger by Denis Sazhin
IMO messenger enables video calls right from your browser
imo Messenger Update Brings Free Video Calling, Broadcast Sharing | Cult of Android
Imo Messenger - supports instant messaging across an impressive 11 networks MSN, Yahoo!, AIM/ICQ, Google Talk, Myspace, Skype, Facebook, Jabber, imo, VKontakte, and Hyves.