FWIW, I have been making a concerted effort to get all my social media accounts set up and linked together more tightly than Mitt Romney clutching a fistful of dollars. You may see my rather broad and eclectic smattering of social media content by visiting The Social link on my blog here.
I recently added LinkedIn, Instagram (couple days before Facebook bought it..lol), GetGlue, Pinterest, PeerIndex and also MopedArmy, a particularly attractive website for a guy in Europe with a moped and time to ride. Expect to add FourSquare at some point in the near future.
I stayed away from Twitter for a long time. Highly recommend it as a resource for breaking news as well as those interested in following the minutia of particularly notable individuals as well as your favorite celebrities, hobbies and any other special interests.