It's a modern filmmaking technique that's been used in big-budget Hollywood features for years now, but a Harvard comp-sci student has developed software that does digital face replacements without the need for a skilled effects artist, reducing its cost.
Using footage from a locked off single camera and a simple lighting setup, Kevin Dale's face transplant software starts by creating a 3D model of the donor and recipient faces. Depending on the footage, the software is able to do this autonomously, but it can be assisted and tweaked by adding facial markers in its UI. Once the models are created, the program automatically morphs the donor face to match the shape and position of the recipient, ensuring that the seams around the original face blend as smoothly as possible.
On your run-of-the-mill desktop computer the software can render a ten second video in about twenty minutes, but presumably that time will increase with added motion in the scene, and higher resolution footage. While it's probably not going to replace the high-end tools used by Hollywood FX artists, as a YouTube plugin it could open up a whole new world of piracy issues, when even an actor's face and performance are used without their permission. [Harvard via NewScientist]