There are heaps of tiny cameras for remote control planes, but if you’re looking for an out-of-the box and low-cost version then you might like this RC Plane Camera from Chinavasion. It weighs a measly 20g (2/3 of an ounce), the camera is mounted on a swivel and it comes with a lightweight bracket so you should be able to stick it anywhere on the plane.
Inside there’s 2GB of storage and you choose to take mp4 VGA video @ 25fps (good for 90 minutes) or 300, 1280×960 stills. The lens has a 70° field-of-view and there’s even a microphone to record hours of nrrrrrrrrrrrrrr. Would probably work well on kites or high altitude balloons as well. ~US$47
This lightweight RC plane camera comes with an easy to install camera mount that attaches to any RC flyer or kite in less than 2 minutes. The camera and mount are constructed from durable yet light weight materials so the total weight is only 27 grams (camera is 20g). This allows you to capture breathtaking videos without degrading the performance of your RC flyer due to excessive weight like most cameras have.