Trillian Basic 3 

Trillian™ is a fully featured, stand-alone, skinnable chat client that supports AIM, ICQ, MSN, Yahoo Messenger, and IRC. It provides capabilities not possible with original network clients, while supporting standard features such as audio chat, file transfers, group chats, chat rooms, buddy icons, multiple simultaneous connections to the same network, server-side contact importing, typing notification, direct connection (AIM), proxy support, encrypted messaging (AIM/ICQ), SMS support, and privacy settings.

Without stealing your home page and with no other included software, pop-ups, or spyware, Trillian provides unique functionality such as contact message history, a powerful skinning language, tabbed messaging, global status changes (set all networks away at once), Instant Lookup (automatic Wikipedia integration), contact alerts, an advanced automation system to trigger events based on anything happening in the client, docking, hundreds of emoticons, emotisounds, shell extensions for file transfers, and systray notifications.

it has universal plug and play , its faster and smaller and it has a whole lot more to offer

On Trillian Basic 3 or Trillian Pro you can chat with your buddies even when they have different messangers

like jerry has yahoo messanger , melissa has msn messanger
, molly has ICQ , and John has AIM you can use Trillion and talk to all of them @ the same time

Trillian Basic 3 by Thaina August 21, 2006