Games Radar has a video clip of their experiences with the first Playstation Network title that uses the upcoming PlayStation Eye peripheral.
Trails of Topoq lets players use bodily movements to push along a ball (marble) through and around a sort of obstacle course. Don't worry though, this is no Totemball. The twist here is players' visages are projected onto the playing field, and their movements cause the playing field to raise in elevation. This forces the ball to roll away from the raised area, hopefully moving it where it is supposed to go.
Games Radar says that they started out by simply doing hand movements, but eventually they had to move a lot more to get the ball where it needed to go.
Trails of Topoq looks to have some very interesting gameplay. I wonder if a long, vertical object (maybe a broom) couldn't be used to "squeegee" the ball across the screen.
[thanks, Mr. Donut]