Howdy,
Moonbounce, or Earth-Moon-Earth propagation, is simply the activity of aiming a radio signal at the moon in hopes to bounce that radio signal to a distant station off of the moon's surface. This is the same thing that is done with "passive" man-made satillites. The radio signal must be above the HF spectrum, so that it will pass through our ionosphere. It must be powerful enough to make it to the moon, and then to the distant station. If the station that you are bouncing (reflecting) the signal to is another Earth station, then the signal must be strong enough to make it to the moon and then back again. Also, both stations must be able to "see" the moon.
The moon was used as a natural passive reflector by the U.S. Army Signal Corps for the first time on 11 January, 1946 by bouncing radar signals off of the moon during Project Diana. On 29 November, 1959, voice transmissions were relayed from Holmdel, New Jersey to Goldstone via this same natural satellite.
The Moon was also used as a reflector of radio waves by the U.S. Army in the 1950s, when the existing channels between the US mainland and Hawaii failed because of atmospheric disturbances.
Moonbounce is another way of amateur communication worldwide on VHF and higher frequencies. When you beam a radio signal at the moon, the returned reflected signal spreads out, and can be received at any place on earth where the moon is above the horizon. One of the biggest thrills in amateur radio is the first time you let go of the key and actually hear your own voice or signal come back off the moon!
Some links:
http://www.hb9bbd.ch/
http://www.dxzone.com/catalog/Operating_Modes/EME/
http://www.af9y.com/
http://directory.google.com/Top/Recreat ... oonbounce/