Facebook is 100% percent necessary for a college student like me. I feel that is a little more mature than myspace in terms of atmosphere. It is more ordered and uniform, which despite my love of custimization, I find a little more asthetic for the social networking aspect. I do get tired of the apps, but I block all of them save for bumper stickers and flair since that is easy to manage and is rather amusing at times. I like seeing the pictures my friends post, and I like sharing mine too. I can't tell you how many of my school's events have been advertised effeciently through facebook. Myspace has a lot of kids on it (of all ages, if you know what I mean) and I don't like random music artists soliciting their acts to me like myspace does.
Myspace would be good if you were into blogging, but there are many free blog services out there...besides, I have my own semi-blog elsewhere (6+ years and still strong!), linked in my signature.