My brother has become a quadcopter hobbyist. Once you learn the ropes (on smaller, less expensive machines), the major application is probably aerial photography. We have a lake home in Wisconsin and here is a tour around our lake. The video ends with the quadcopter coming into our beach.
I must admit that I would be intimidated flying anything as expensive as a quadcopter and camera over water, but I guess you get to the point that is what you do. The GoPro will record video in 1080p. I downsized to 720 to reduce the file size. Still, the quality of the video is pretty impressive.