Seeing how people are starting to dig up that iconic Power Mac G4 cube and reuse them for all sorts of personal pleasures, we believe a roundup is in order. Here's a few things you can do with that amazing acrylic box in case it blows up (or has already blown up, taking up room in your closet).
Turn it into an aquarium.
Use it to hold your Mac Mini, external hard drives, and Airport Extreme.
Turn it into a custom computer with built-in LCD.
Turn it into a modern hanging lamp. The above picture is actually the Ice Cube Lamp, but it looks almost exactly like the G4 cube hanging from a wire - a simple DIY should do the trick.