If you want to know more about the inner workings of DYI multi-touch, you'll be interested in the video below.
Aaron Bitler and Brady Simpson learned how to build a multi-touch table through their participation in the NUI Group, and recently formed a company, 3M8 to distribute multi-touch solutions. The 1/2 hour video provides an in-depth tour of multi-touch technology, in an an on-line broadcast on the HAK.5 website.
"Brady Simpson explains the different multi-touch methods. Aaron Bitler gives us a tour of the x19 multitouch tables construction. Brady explains the software used to power the x19 lcdmultitouch table, including the nuigroup CCV application. Aaron wraps up by explaining to us how he got involved in multitouch. He shares with us some sites where others can get started in their own homebrew projects, as well as his own multitouch company 3M8s at LCDMultiTouch.com."
UPDATE: New website for Brady Simpson's company: http://www.lcdmt.com/