I thought it usually takes a week or so to get a title mailed to you :/

But if I were you I'd be going to the police and having them put some sort of note on the VIN of the car you traded so that the new owner cannot register the car until you get a LEGIT title for the new car.

edit: or just tell the guy you're going to report the car stolen and say the title was in the glove box just to scare him a little bit.