Danah Boyd has written a clever essay titled "Friendster lost steam. Is MySpace just a fad?" that examines the successes and failures of Friendster and MySpace from social and technical perspectives. Lately I've reluctantly started to embrace MySpace due to the fact that it's the first online space where most of my IRL friends have entrenched themselves.
It's interesting to watch the evolution of social networking websites. They keep getting weirder and more "real".