It's a long shot. I know sometimes when you see a total MILF in the grocery store you overflow with the urge to spread your seed, but unfortunately women aren't as keen on the idea when you are a complete stranger.
One thing I have thought about doing is walking up to hot girls that are total strangers on campus and just say something real dirty about what I would like to do to them. You know, toss the salad, lick my cum off their tits, etc...Sure, I will get a lot of negative reactions, but inside they will be turned on by a man that is willing to be so upfront about what he wants, and she'll probably go home and masturbate about how hot it would be to let you do that...