I was never in a frat seeing as I went to university* in the wrong part of the world! Are fraternities a uniquely American institution (I don't think I've heard of any existing anywhere else)? I really don't know much about them (or even what they do), although I've certainly become well-acquainted with at least the concept of them through their portrayal in movies and on TV shows. Judging from those same films and shows, I gather there are other ways in which institutions of higher learning in the US differ from those here in Australia. Down here, for example, students don't live on campus as I gather they do in the States (so I missed out on the experience of having some wild roommate as well!).
To touch on a subject a few of the other posters have brought up, I toyed with the idea of joining the armed forces at one point (after I'd dropped out of Uni in my case), and went as far as applying to join the "sapper" division of the Army Reserve (from what I heard, one of the more macho branches of the Australian Army, although I didn't find that out until later). My motives for trying to enlist had nothing to do with my CDing (which I was already comfortable with at the time); it just seemed like something interesting to do. In any case, I failed the preliminary psych evaluation, for I ended up giving the evaluator the impression I was a transsexual on the verge of getting SRS (and probably barking mad as well!). Oh well.
*Are university and college the same thing in America, or entirely different entities?