I follow a lot of fighters on Twitter. It's a great way to interact with them and stay up to date with what they're up to. It's the second place I go to for MMA news, after this site of course. Not to mention that it's a great way to promote fights. Facebook is good too. If it wasn't for the fights on facebook, we might still have un-aired fights.
Btw, @bdanleaman <---- that's me