...I have the Garlic App. It's pretty good, vibrates when there's one of those bastards in the proximity. Cons: I dunno if it's a pro or a con, but your Droid always smells like garlic. On one hand, coworkers are always asking you what bagle shop you go to for breakfast. But on the other hand, in a room full of strangers you can pick out a vampire real easily; it the one that's constantly staring at you from across the room cause he smells that Garlic App.
Author of that same app is currently working on the wooden stake app. That one will be a 3 bucker for sure.