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    

For now it works on leftovers, but I imagine it could easily run on all kinds of waste in time.

Leftovers battery. English researchers have built a battery that runs on table-scraps.

Inside the battery, which is the size of a personal CD player, a colony of E.coli bacteria produce enzymes which break down carbohydrates and release hydrogen.

Chemical reactions inside the cell strip electrons from the hydrogen atoms to produce a voltage that can power a circuit.

Scientists say 50 grammes of sugar would keep a 40-watt light bulb lit for eight hours.

Link Discuss (via /.) [Boing Boing Blog]

Assuming that the hydrogen output is sufficient, you could have the tanks at your sewage processing plant provide local power for streetlamps, or serve for co-generation year round, easing the burden on the grid.

10:11:09 AM