Ask HN: Location Based Dating?

Hi HN-

I posted this last night, but didn't really get much response. I figured I'd give it one more shot, since I think there is some upside to this idea. Obviously I wanted the opinion of the collective.

So, A buddy of mine recently told me to take a look a blippy. I liked it, kind of. In any case, I thought that this voyeuristic (or insane sharing) impulse could be put to use for dating. What does that mean? Well I think with user's permissions you could attach to their foursquare, blippy etc. (or use the api if one exists), gather up their recent check-ins/location data, and then compare with other people who have similar habits. People with the highest matches could be recommended first etc. etc.

Yes/No/Already Exists? What do we think?