I spent an afternoon in Oregon a few months ago trying to hook up my GoPro camera to a box kite to get some sweet aerial footage. In short, it was pretty much a failure because the extra weight of the camera de-stabilized the box kite and it oscillated wildly until it crashed. I still plan to work more on getting good aerial footage from a kite, and this process will be aided by the help of this website:
http://arch.ced.berkeley.edu/kap/kaptoc.html
Check it out!