The "many worlds interpretation", parallel universes, the Trousers of Time: call it what you will, but quantum theory has some surprising ideas about what happens after a quantum event, which artist Jonathan Keats is exploring in this new "toy". It's a ball of uranium-doped glass (no, really—it's uranium!) next to a scintillation detector crystal inside a jar. The idea is that as the uranium decays and emits particles, the detector "observes" this event, and splits off new universes as it goes. It's all quantum. And it's pretty crazy. But if the god-like novelty of having a universe creation kit on your desk tickles your fancy, you can buy one for $20. [OhGizmo]
This reminds me of that episode of Earthworm Jim, where the universe was just inside a snowglobe.
I'd rather just have a sealed-in aquatic ecosystem. They sell some at Brookstone with red shrimp and algae inside, but it's more fun to make one yourself.