After watching the absolutely amazing 10/GUI video, I have been dying to try to implement something like this. I can do the software side quite easily, but I don't have the hardware.
The Wacom Bamboo Fun would work, but the Linux drivers don't support the multi-touch features.
Microsoft's "UnMouse Pad" looks like the perfect solution, but it is not commercially available yet.
Are there any similar devices that would work? Alternatively, is there a way to build a DIY version? (It is fairly easy to build a multi-touch display with a webcam and IR LEDs, but it would not be pressure sensitive. Does anyone have any info on how the UnMouse Pad works and if it is possible to build one?)
EDIT: I should clarify that I don't want a multi-touch display. I want the sensor to be separate from the display. If that sounds crazy, watch the 10/GUI video.