I'm looking into a build where weight is very important and needs to be minimized (it flies). I want to be able to detect objects and path around them, using a raspi as the brain. My first thought was perhaps a visual sensor like a webcam (would I need two of them for binocular vison?) -- the Kinect would be ideal, since it was designed to do depth detection, but it weighs 3 lbs!
What kind of hardware can I use to keep the weight of the entire build under a pound? Not looking for specific products necessarily, just a sense of what I'd need and if it's possible.