Seth Sanders created a low cost multi-touch system called MT mini. It uses
TouchLib which is a C++ library (
Anyone want to see if they can't get it working with .Net?) I'm not sure but I think a few of the demos were from the TouchLib system, the keyboard is
To get it up and running, you can check out his forum post.
Update: Daniel D commented there is a .Net project over at CodePlex that uses TouchLib called Multi-Touch Vista. They have videos too!