Coming to an Apple Store near you: this thing, that I am completely in love with. It's called the BackPack, and it clips onto the back of new iMac and Cinema Displays, creating an instant shelf for, you know, things.
The stupid-simple contraption fastens to your Mac's stem with a couple of non-scratch clips, and is kept in place by nothing more than gravity and friction. And you can connect more than one, turning your computer into a brushed aluminium shelving unit, just like you never knew you always wanted.
The shelves are primarily intended for accessories, such as external hard drives, USB hubs, and docked iPhones, though they could just as easily be used to store non-digital items, like dead tree office supplies, or an emergency sandwich. The possibilities, they are endless. Apparently Apple sees the cleverness in the concept too, since they're planning to carry the BackPack in their stores, for $US30 a shelf, or $US150 for a pack of six. [BackPack]