If I can go around i do. if not, I flash the high beams a couple of times.. if that doesn't work I get on their tail and then back off then get on it again and do this a couple of times...
If this doesn't get em, I wish i had my laser attached tot he hood star and aimable so I can take out some road rage on the one who has given me a hard time passing.
Though I find I don't have to do this, because people see me coming, and they usually move, otherwise if theres room, they wont have time to move, I'll be passed them by the time they realize it.
Alon