Help!

Oh god, I'm trapped in the MSN conversation from hell! Some moron added me just from profile surfing, and I accepted it because I thought it was someone I knew. Bad move. He's really not so swift, in both the figurative and literal sense. I really feel like being rude and just disappearing, but I don't like to be rude like that. So instead I'm being passive-aggressive rude in the conversation, hoping he'll lose interest. No such luck.