I want the smallest USB 2.0 hub I can get hold of. It needs to be able to fit in a PowerBook case, at least once the casing and ports are removed.
My 15" 1.33 PowerBook G4 has its bluetooth module right at the front, just to the left of the trackpad. If I can find a hub small enough, I can fit something else in line with the bluetooth board. Either an iSight Camera or an IR receiver. Or both.

Looking at the device tree, I think the bluetooth is hooked to a USB 1.1 bus. Won't be much use for an iSight though.