Love this technique! This only took a couple hours, but finding spare time this week has been challenging. I just set up the camera and filmed several hand gestures videos - thumbs up, thumbs down, fist bump, count down, and a few others.
Like Linda, these were done completely with Photoshop CS by importing the video, reducing the frame rate to 12fps, and then exporting video frames to layers.
Once all the frames are in layers, start tracing, painting, adding color, or anything you want. Once done with styling, render the video and simply export layers to animated GIF.
I started building a True/False type interaction with a 'thumbs up' and 'thumbs down' animated feedback. Finished the two feedback GIFs, but have two more videos to complete the design. Decided to record the process in a tutorial and started that today. It'll be a few more days before I wrap it up, but thought I'd share this piece now.
https://s3.amazonaws.com/nuggethead.net/animation/rotoscope/story_html5.html