I have seen this driving by the community pool a few times. I don't know if they do it for cooling or aeration, but it looks pretty cool! In case you have trouble seeing it in the video, it is a pool pump mounted on a wheeled base with a line that is dropped into the pool and it has twin pvc sprayers for output aimed into the pool.
http://s138.photobucket.com/albums/q242 ... CT0049.mp4
http://s138.photobucket.com/albums/q242 ... CT0049.mp4