I performed a simple search of boards and can't believe there's no hits for "Leap Motion" controller, unless the boards search facility isn't great...
It's only $69 on pre-order, and ye are probably many tens of thousands behind in the pre-order queue already.
I'd expect the same backlog as with the Raspberry pi.
I applied for the free developer kit, early access to the SDK and a free pre-production version of the device and they accepted today
Now there's 10,000 free units but already over 60,000 applied I believe.
Anyway, it's one to watch.
I love the idea of it being a sort of poor mans 3D scanner.
It scans a 4 foot squared area in front of the controller, and the later version of the SDK will give you direct access to depth buffer.
But the early versions detect the number of hands and fingers in the zone and the exact orientation of them. It's ultra accurate too, sub-millimetre.
Anyways, thought I'd raise awareness of it.