How annoying. We've had quite a few of these hanger-ons at our apartment (my roommate seems to collect them) and they're quite a nuisance to get rid of. They're worse than ants. >.<

Hang in there. Eventually, he'll find some new target and amble aimlessly off. The nice thing is that, usually, these guys are so... out of it... that they really don't do much except send the occasional text message. They're harmless (though that doesn't make it any less creepy).