Watch this, then read up. I expect to see this in commercial applications of self propelled robots in the next seven years. That's based on the progres of bipedal robots as well as the advances in energy/fuel cell technology.

Robot hand and vision snatches objects from the air. This robot hand, coupled with a computer-vision system, is freaking eerie. Click through for a bunch of MPEG clips of the robot's master taunting the hand by waving objects before it, while it, and its vision-mount, chase them, eventually reaching out and snatching them out of the air. The hand-shaking demo is killer. Link Discuss (Thanks, Matt!)
[Boing Boing Blog]

It looks like high contrast items are needed for the tracking system to work optimally, but a combination of sonar overlayed with ccds and IR would likely make that less of an issue. It appears that vison is done through a video camera that tracks the moving obkect, and in turn controls the arm. Also, interesting reflex action with the thumb serving to close the hand once contact is made.

Hmm, as I watch more of the videos I'm less and less impressed, It looks like the handler is actually all but feeding the objects to the arm, not unlike teaching a kid to catch a ball by placing it in their hands. That's a shame really.

11:22:46 AM