Unmanned Aerial Vehicles. They're like model airplanes, but way bigger and a lot more useful.
[link|http://abcnews.go.com/sections/us/DailyNews/military_predator.html|Predator UAV]
[link|http://uav.wff.nasa.gov/|NASA's UAV page]
[link|http://www.af.mil/lib/afissues/1997/app_b_16.html|Air Force UAV page]
[link|http://nationaldefense.ndia.org/article.cfm?Id=402|UAV and coastal warfare]
[link|http://www.unmannedaircraft.com/|A site with lots of pictures]