Backers hope they will prove a cheaper alternative to helicopters and fixed-wing aircraft for tasks as varied as power and pipeline inspection, mapping, security, border surveillance, research, filming, fire fighting, search and rescue and delivering supplies.

ECONOMIST: A small Welsh airport has become an unlikely tech cluster

"The cease-fire enabled us to conduct disease surveillance with the freedom of movement, not fearing land mines and getting shot, " said Dr. Nabil Azziz, who coordinated Sudan's national Guinea worm eradication program until 2007.

CNN: Guinea worm a greater challenge than smallpox

Former President Jimmy Carter negotiated a cease-fire in 1995 to allow health workers to conduct national Guinea worm disease surveillance, treating patients and tracking cases.

CNN: Guinea worm a greater challenge than smallpox

Monti's reconnaissance team occupied a surveillance position when they were attacked near Gowardesh, Afghanistan, and he was killed by enemy fire, the Web site says.

CNN: White House: Soldier to receive Medal of Honor posthumously