Perspective from a student in college:
Facebook is a great way to keep up with events going on or around campus. Without facebook, people will be less prone to invite you to parties and events.
As for usefullness, I use it as a tool to keep up with high school friends, relatives and form closer bonds to college friends I already have. However, facebook should never be used as a tool for making friends outright. It really only works best after you have established some sort of comfort level with the other person in real life, or else you constantly liking their statuses or posting on their wall will make you look like a creep. Remember, it is alot easier to look like a creep on Facebook and not realize it than it is in the real world.
Personally, I say you join it. Add relatives, add some coworkers, add some friends. See how you like it. If you don't like it, then you could probably still get by with the old fashioned way of calling people on their phone. However, in my age bracket, it is VASTLY easier for people with Facebook and unlimited texting to have a social life than it is for people without these things. That isn't to say there aren't students without these things, but many people, including myself, don't want to be bothered with emailing you and singly calling you in particular if we are all just going out somewhere really quick, or planning a big party. We are really only willing to do that for good friends, while a person who I'm not great friends with would still get an invite on facebook.
Hope that clears it up for you.
Also if you join, don't update your status everyday, and don't update it with stuff like "I'm hungry." or "Going to the gym in 5 minutes." That doesn't stimulate conversation.
Also, I disagree on the whole "you get to see women outside of that bar setting" mentality, since women can selectively choose to show pictures in which they become the worlds best body contortionalists and look like super models. Just saying.