Adium has been a long-time favorite of many Mac users. While the free program started as a basic AIM client several years ago, the program now can connect you to not only your AIM buddies, but Google Talk contacts, MSN and Yahoo! chat buddies, and Facebook friends. Add all that to an interface that allows endless customization, and you get one slick app.
But there has been one hole in Adium for a long time: Twitter support. That’s changing: