I Heart Diapers
Not the wiping of butts that goes with them, of course, but rather their usefulness in disposing of incendiary or compromising items. Got a receipt for a mountain bike part that you don't want your partner to see? Need to cut up your old credit cards but are unsure how to dispose of the bits? Diapers are your solution! Once you wrap a small item-to-be-disposed-of in the middle of a soiled diaper and put it in the trash, I guarantee that no one is ever going to find it.
I write this with more than a trace of sorrow, as we're going to start potty-training Leelo in three weeks.