>>"Go get some LSD and put it in the OJ or something. I guaranty you that leech will think twice about eating your food again."
agreed. but hey, to keep it legal, spike it with DXM (dextromethorphan)...
or, if your really bored, put say, a fish eye from a dead fish on a peice of paper, tape it down, along with some pennies and nickels, and write "i've got my eyes on you, here's some money so you can go buy your own food"...leave it on top of your food or something, so that he'll find it if he goes searching.