Came across this and thought I would share. Its called Touchless and its from Microsoft. Its opensource [ya I know never thought Microsoft and open source would mix either]
Touchless enables touch without touching by using a webcam to track color based markers.
This project is an Office Labs community project, which means a Microsoft employee worked on this in their spare time. It is also an open source project, which means that anyone can view, use, and contribute to the code.
Looks kool. I have not had a chance to test it out tho. As soon as I find some kind of yellow tennis ball or something I will have to try it out 
[Source: OfficeLabs]
-Tracker
