I second Swing. I've been doing it for 3 years, and it is great way to get exercise, just take a look at this if you don't believe me. Of course, it doesn't start out that fast, very few people, even those who have been doing it for years can't dance that fast for any amount of time.
Plus, it has a very goofy, carefree attitude, which can be easier to approach than the intense, "stare passionately into your partner's eyes" that the Latin family of dances tend to have. Just about any lack of skill can be excused by a big dopey smile.
Lastly, and I have no idea why this is, but swing dancers tend to be techy. At my local scene, almost all (no joke, like 80%) of the guys are either Computer Science or Computer Engineering. The girls are a bit more diverse, but cluster around biomed or applied math/econ.
But the advice of the parent is essential. If you make it clear that you are there to pick up girls, you will quickly become "that creepy guy." On the other hand, I've known fat old guys whom all the college girls are lining up to throw themselves on, so attitude plays a huge part.