The last video I posted has a website:
Image Metrics On the main page is a PLAY button, click it to see a demo of original video and animated CGI character. Oh, be warned, one of the gestures she does is a pretty loud yell after showing off an angry pose! XD
This link will take you to a short video of how it's done, a behind the scenes clip.
http://www.image-metrics.com/videos/231 They've done work for film, video games, the works, including GTA IV among many big name titles!