Facebook. I kept telling myself that I wasn't going to do either...and then someone wanted me to look at their pics, so I had to sign up. And then one of my sorority sisters sent me the facebook link. More of my friends are on Facebook, and they're easier to find. People generally stick with their real names on facebook instead of labeling their profile "Fartface" or whatever.
Plus, less annoying flashing glittery stuff or random bad music.