Night vision might be designed for use by Navy Seals, but I'm going to go out on a limb and guess that it's used a lot more by perverts and pranksters these days. Adding credence to my theory are these Night Vision Goggles from the Discovery Channel Store. Yes, they'll allow you to watch your houseguest sleeping without turning the lights on, but they have the added bonus of having a built-in dart launcher as well. Holding five suction-cup-tipped darts, it also comes loaded with some bright LED lights to add to the sadism. First you blind them with light, then you nail 'em in the eye with a suction dart. You're sure to be a hit, as nothing's funnier than getting blinded twice in a matter of seconds while getting up to pee in the middle of the night. Instant annoyance can be yours now for a reasonable $20.