Recently we've been digging astronomy gadgets around these parts (and astro-mashups on Webware). Most of the time, they deal with plain old stargazing or the simulation thereof. This Japanese import, however, deals with recreating the Aurora Borealis (Northern Lights) on your wall, ceiling, or projector screen of choice.
The gadget in question is a 6-inch-tall lamp, retailing for the Japanese equivalent of slightly over $60, which runs on AA batteries and even comes with a sleep timer so that you can use it as a sort of visual lullaby. It obviously isn't an exact scientific reproduction, but for those of us who don't get to see the Northern Lights on a regular basis, it probably has a cool novelty effect. And as always, don't underestimate its potential as a party gadget.