JVC has been working with gesture recognition and gesture-controlled TVs; the device was covered to some degree in a previous article. See JVC Clapper Gesture Recognition TV for more details.
The basic idea is that the television user's hand gestures are tracked by a camera; particular gestures can be recognized, and used to control the TV. Your hands are the remote! Just try losing the remote now.
Take a look at the video to see how JVC gesture recognition and control televisions work.
There was a recent flap about whether or not Comcast was discussing using units like this to actually see more than gestures. If it is possible to recognize gestures, it is also possible to recognize individuals, and to recognize individual expressions. (For a real-world example, see OKAO Vision Lets Machines See You Smile.)
So, in an ideal (Comcast-controlled) world, if the TV saw that you were looking bored, it could immediately perk you up with fresh content, based on its knowledge of your personal viewing choices.
However, in what one assumes is an official reply, the Comcast VP in charge of user experience explicitly denies that anything so Orwellian is being planned.
To gather information for your article on Comcast's exploration of cameras you picked up on my conversation with another conference attendee. The other attendee and I were deep in a conversation discussing a variety of input devices offered by a variety of vendors that Comcast is reviewing.
The camera-based gesture recognition device is in no way designed to - or capable of - monitoring your living room. These technologies are designed to allow simple navigation on a television set just as the Wii remote uses a camera to manage its much heralded gesture-based interactivity.
I find this reply kind of sneaky and Comcastian. The Wii only monitors the position of the controllers. A gesture recognition camera system looks at you and anyone within range. All of the features mentioned above become possible with a camera in the set top box trained on the TV viewers.
Anyway, if Comcast tries putting a camera in my set top box, for whatever reasons, I have the perfect gesture planned.