I've been really liking the Sichuan peppers (aka Szechuan peppers) I got from the asian grocery. Although they look like peppercorns, they're not related to black pepper or chili peppers. They give a numbing or tingly sensation with a little bit of lemony tang. They work well in a hand grinder for black pepper, which is good because Julie won't let me put them in anything she eats.
I bit my lip the other day, so I tried grinding up some sichuan peppers and applying the powder as an alternative to benzocaine. It worked, but I think the (unrelated) Szechuan buttons (aka toothache plant) would work better. I'll have to try to get some from the guy at the farmers' market who subtly sprinkled some petals in my hand, giving me an electric surprise.