DeadAIM makes AIM better.
Rename the screen names on your buddy list.
Customisable buddy list.
Tabbed instant message windows.
Window transparency effects.
Logging of conversations.
Logging of chatrooms.
Logging of events (e.g. sign on/off).
Logging of images and sounds.
Log search ability.
Ability to talk while set away.
Ability to run multiple AIMs (cloning).
MSN style popup notifications.