Some of my readers have proposed to combine skeleton tracking with finger detection but I haven't tried this yet. And here is an example why: I've found this video (already 2 months old) in which Patricio Gonzalez demonstrates a combination of the two techniques.
The problem is that for the skeleton tracking to work, you must be far enough away from the Kinect. And for the finger detection to work you have to be close enough. This defines a range in which both algorithms work, but in my opinion that range is empty at the current resolution of 640x480. I guess when the depth cameras provide a resolution of 1024x768 plus, we will quickly see this catch on.