I've long thought that these things are a great idea but somewhat constrained by the actual hardware. All you need is a multitouch surface a la Jeff Han, and the appropriate software- yes, it wouldn't be as portable as that device but it could have a high-res colour display and maintain the same input method (minus tactile feedback of course).

The hardware is already out there, and I'm sure the software is within reach of someone who knows what they are doing. Even if it wasn't open source, you'd still be looking at a couple of hundred pounds as the going rate for sampling software, not 900 squids for a hand-polished magnesium Lite-Brite.

Nine hundred and nineteen of your English Pounds! Quick - somebody create their own!