Transparent fingers of fun

Neat idea: make PDAs transparent so you can put the touch screen on the back side, and still see where your fingers are to select stuff. That leaves the front side able to display everything, means you can hold the device and still use all your fingers for selecting/typing/whatever, and your touch technology doesn't have to be integrated with the screen - making it more robust and cheaper.

Problem: while we do have transparent semiconductors (if you're reading this on an LCD monitor or laptop, you're looking through millions of them right now - they coat the front of active liquid crystal displays), they're not suitable for building complete computers.

Solution: overlay a shadow-like outline of your finger positions on the main display, so it looks as if you can see them.

This is what researchers from Mitsubishi and Microsoft have done, as reported (with engaging video) in New Scientist this week. It's very prototypy - the sensor that works out where your fingers are is a webcam that's mounted on a big stick bolted to the PDA - but that's OK. There are plenty of ways to integrate a more sensible sensor, if the initial experiments work.

And if they don't? That's OK too - this is what research is all about. (And, in passing, how uncommonly pleasurable it is to write something good about Microsoft. I'm sure you're as sick as I am about the same old same old... but what can a man do?)