Join everything, do everything, meet everyone.
Take a look at Mark Redman's Ebook: Conquer your Campus
http://www.conqueryourcampus.com
In college, all the girls expect to meet a guy in their day to day life, so be throwing yourself into everything, you maximise your potential and ability to be the guy that girls meet, and therefore raising your social value by knowing everyone and also increase your invites to parties, invites to go do things and just generally how awesome your life is.
Also, if you have time, check out Braddock's talk on College Game
http://www.the21convention.com/2009/05/ ... pe-1-of-1/
From Day 1, everyone is out to meet everyone, be the person that goes out, has fun, can introduce people that will get along and be just genuinely THE SHIT. Be the coolest guy ever.
--------Be the guy you want to be around--------------