Julie Johnsson has a nice piece in Businessweek about how Boeing is buying up old 747s in order to sell more new 747s, referring to "desert storage" of the planes that are going to be taken out of service in hopes that at some future point someone will want them. Desert storage? My interest was piqued. And of course it makes sense. The arid temperatures of a desert are a good place to store complicated machines that you don't want to corrode.
The facilities are called "boneyards" and the largest one is outside Davis Monathan Air Force Base in the Tucson area. Here it is courtsey of Google Maps:
Except this is zoomed way out, so you can't really see. Look closer:
Nestled between the suburban subdivisions are tons and tons of airplanes:
This is an air force base with military aircraft (UDPATE: civilians too!), but here you can see civilian planes parked outside Mojave Airport:
The standard application for old 747s is to convert them into cargo use, but structurally higher fuel prices has really cut down on demand for the aircraft. If the unconventional oil optimists prove correct and jet fuel gets cheap again, the mothballed 747s will presumably come out of retirement and start doing cargo duty. If not the planes can always be broken down for scrap.