Your search for the "webcam" tag brought up 2 results:

E-Zine: The Shuffled LFO tut

Like any ol' dubstepper, we were wondering what might be the next step up the ladder of funkiness. As an answer this tutorial won't suffice, but it might just point you in the right direction.

E-Zine: Midi input over webcam in Ableton

Learn how to input notes in your favourite sequencer by only using hand signals and a webcam!