Trillian·Ah, there's nothing like falling in love with a new piece of software. Trillian is an instant messaging service that connects to Windows Messenger, AIM and Yahoo IM users, all at the same time. I'd tried Trillian before, but it used to crash my machine.
The latest version seems stable, and it's the best piece of personal software I've come across in a while. Obviously, there's one single list of buddies online, regardless of the three main IM systems they use. The software lets you rename contacts, which means you can get rid of their silly screen names.
The default Trillian look is a tacky console, but there are other options. Download the Windows XP skin. It looks just like Windows Messenger, but there are little icons, indicating the service used by the online buddy. See the screenshot to the right.
TrillianWindows XP skin