For those interested in the theory that goes into the practice, here is an article discussing the limits on [flying] maneuverability in cluttered envrionments. Inspired by abilities of birds, but ‘simple’ enough to soon be available for use in UAVs.
Found an article about some research to allow navigation / position detection where GPS does not work. Bigger systems already use this technology, but the research is to develop it for use on small resource and battery life constrained devices, like cell phones. That will also apply to small, mobile, indoor robotics projects.