facebook sucks, the only use is to find out who else is in your classes BEFORE class and find out all their info so you don't have to ask them during class lol. and just be like, facebook me. then you can exchange answers for HW and such. or just rant about how the teacher is a big prick/bitch.
myspace on the other hand allows me to discover new music that rox as well as comedians, and watch videos of of people playing instruments who are better than me, or even post a classified ad to look for that missing guitarist for my "band".
Facebook has nothing on myspace, except for a small userbase so it feels more private and you don't get that "omg U R so HOT!" msgs, then again i don't get those that much on myspace to begin with so yeah... facebook sux in comparison, but that doesn't mean it doesn't have the uses mentioned above. (aka as soon as i'm done with school you can kiss my facebook good bye) (also myspace has all the privacy functions and college groups too, but its just not the focus of the site, nor does anyone seem to use it)