Gaming Table

Somewhere I saw this great video of the Microsoft Surface at It is a demo of computerized D&D on a touchscreen tabletop surface. I was thinking about whether or not that would be possible without buying the Surface (which I’m guessing is expensive). I thought of tipping a flatscreen monitor or TV (depending on how big it is) and placing two cameras, probably webcams, along the edges. Each player and the DM would have colored tape on their fingertips to show who it was. The cameras would be connected to a computer, which would have to know where the cameras where in relation to the table, which would then track peoples fingertips. Another possibility I was thinking of might be StrechTight ™ over the TV, with some sort of pressure sensor to track when it was pulled tight. What do you guys think?