Researcher danah boyd has produced a new study of Facebook and MySpace users, finding that the differences between the two have more to do with class than age or other factors. Facebook is attracting more affluent, middle class young people who have a focus on college and careers; MySpace seems to be attracting more minorities.
Faculty that are looking at social networking as part of class activities might want to examine both sites closely; the different audiences for them could make for interesting class activities involving student research.