Yep, I've thought about using a kite for signalling, both as the rescuee and the rescuer (where you believe or hope that the lost person is able to come to you if provided a fixed reference point).

I figure if worst came to worst, I could make a kite out of a space blanket and some stout twigs, as long as I had a space blanket and some suitable cord. (The inner strands of a length of paracord, tied end-to-end with fisherman's knots, would probably suffice.) Left-over pieces of space blanket, tied to the paracord sheath, could form the tail. Probably, the most expensive component would be the paracord, which would be pretty much destroyed in the process. Still and all, the total cost would probably be less than the price of a movie with popcorn (and probably lots more fun) <img src="images/graemlins/grin.gif" alt="" />