I bought a some of these ZipLinq power-cables a couple weeks ago — they've got a two-prong US plug on one end, and a figure-eight plug that fits the transformers for my PowerBooks, ThinkPad, and many other devices on the other. A quick tug makes them reel back into a compact, tangle-free package.
I love retractable cables, they're the next-best thing to wireless. Power-brick-and-wire assemblies are always problematic, as they require coiling up two wires, making packing up a laptop into a protracted pain. This thing is such a delight to use that I find myself taking it out of my bag just to show it to other laptop junkies.
At this point, I'm ready to replace every power-cable in my house with one of these.
