Everything except for some of the Google X Labs projects, of which this is one.
I'm going to take an optimistic tack and say they're doing this for the PR benefits of being seen as creating new technology that gives people tools they never thought they could have, somewhat like Microsoft has done with the Kinect.
I'm going to take an optimistic tack and say they're doing this for the PR benefits of being seen as creating new technology that gives people tools they never thought they could have, somewhat like Microsoft has done with the Kinect.