Terrific stuff, you can do a lot with OpenCV right out of the box. The Python bindings are pretty poorly documented, though (they change a lot). As much as I'd rather write Python than C++, if you're not already familiar with OpenCV it can be a lot easier to learn with the C++ version. There's a great introduction and API rooted here: http://opencv.willowgarage.com/documentation/cpp/index.html
Shameless self-promotion: If you're interested in face / eye tracking, email me or keep tabs on http://www.gazehawk.com.
Just try to keep in mind that when someone says "I built X in just Y hours" they tend to omit the "and have spent Z years developing the skill set required to do that."
Headroid's author here - yes, the background skills took a fair while to acquire.
As a kid (I'm 34 now) my late father (hardcore electrical engineer) used to bring home electronics junk so I could build robots aged 10 (solder+Commodore 64 joystick port+Lego+Basic). Then I got bored of robotics for a long time.
For 11 yrs I've worked as an A.I. consultant after an AI degree/MSc, recently I wanted to hack, play and build fun stuff so I setup the AICookbook.com with Google Group and I'm posting my play-time projects. Headroid is one of them, there's also OCR (see the Plaque entry on the blog), NLP, recommendation engines, data mining, game play (auto Zork solver anyone?) and more to be done. I'm also a part of Brighton's HackerSpace (BuildBrighton.com) which is where I met BotBuilder who built the servo board and frame.
All are welcome to come join the fun :-)
You should watch the video he links rather then assuming something. HP developed some video drivers for face tracking that didn't handle the "edge-case" of a person with black/dark skin.
Shameless self-promotion: If you're interested in face / eye tracking, email me or keep tabs on http://www.gazehawk.com.