A friend recently linked me to a blog post on okcupid's site. Okcupid is one of those online dating sites, but has a surprising amount of concrete data backing up their research. At the very least, they give interesting results.
One of the first conclusions they presented was slightly unintuitive, yet seemed to make a fair amount of sense. One's penchant for beer is one of the best predictor's of whether he/she will have sex on the first date or not.
They also have a rather fun question for predicting a date's political leanings.
edit: fixed link.
Edited, Feb 9th 2011 6:20pm by Allegory