A (touch) screen technology to identify several input devices
I've had a look at your question and the responses you've received, there's some really good stuff there and a few technologies have been pointed out that - as far as I know - are the closest thing that exist to the technology you're looking for namely, the original Microsoft Surface (before it was a tablet, I think they've renamed the technology PixelSense now) and Reactable/audio Cubes which gbulber linked to.

In addition to this though it is probably worth understanding how touch screens work, essentially they are made up of five parts that can all be wrapped up into a single package.  The parts are:

1 - A video screen or display.
2 - A touch overlay
3 - A touch controller
4 - A video source
5 - Something to interpret and do something with the touch data

The touch overlay and controller come as a pair, most new phones and tablets will use what's called a PCAP touch overlay, that's a projective capacitive touch overlay, and a matching controller, the technology used in both of these parts define how many touches it can handle, the most I've ever seen for a smallish screen (12") from a PCAP overlay is 16 but there may be more out there.

In a Reactable table, the touch overlay is replaced with a video camera the touch controller and the thing that interprets the touch data is replaced with video processing done inside the same machine that produces the video source but the basic principles are the same, you have something that makes video, something that produces touch or location data and something that interprets it and does something useful with it.