What social network should you be on?

I’ve really only bothered with Facebook, but apparently that makes me out of the loop with some 80% of the world. It’s a bit curious that certain social networks are popular with specific countries, some that aren’t even on the same continent. For instance, Orkut is wildly popular in Brazil and India. In America, MySpace is king, though by far for the 20-something generation, it’s Facebook. Take a look, and see what you’re suppose to be using.