Thanks to the new Second Life Viewer 2 you can now place a box on your avatar’s head and hook it up to a stream from your web cam (similar to showing a youtube video on a prim) such as with a free service as Ustream.tv. This allows you for the first time to have your real life face in the virtual world of Second Life in real time for video conferences or whatever.
Check out the below high definition video demo which used a live video stream. And yes that is Ashton Kutcher. Go figure that guy is involved one way or another with all social media revolutions. It is about 3 minutes long.