This looks great! Recently I've been wanting to make a hand-tracking library for video editing. I'd make a hand gesture like an OK with my index and thumb to begin recording, and when I was done I'd make a thumbs up to keep the take or thumbs down to delete a bad take. That way, I could very easily record stuff while only keeping the good takes, to sort out later.

Hell, the library could even stitch the takes together, omitting the times when my hand started/finished doing the gestures.