The Homestar Spa by SEGA Toys turns your bathroom into a planetarium whenever you're taking a bath. You just fill up the tub, strip down to your birthday suit (or a towel if you're a prude like the chick in the photos), and hop on in. Then, with a flick of its switch, the $70 unit instantly fills your bathroom with hundreds of trillions of millions of "stars". Not feeling stars tonight? No problem, flip the unit over and hit the switch again to fill the bottom of your tub with a, uh, bloody mess.
Sega's Homestar Spa: Planetarium edition [engadget]
Thanks to Julian, who calls the model in the photos despite her obvious prudishness.