How about making a multitouch desk or table.
I bet you could blow this one out of the water.
people have done them before but they must be "tall" because you have to put a projector inside of it and they have very little support for actually interfacing with the actual computer just programs that are meant for it
alot of them use mirrors to shorten the distance needed for them.
they can run all programs just like a touchscreen pc.
