During World War II, US Army airborne forces needed a cheap dispatch vehicle that could be easily dropped by parachute into the field. The Cushman company, then producing scooters, quickly converted its line to fill military purchase orders with the Model 53 scooter. Harley Davidson and Indian picked up the slack to produce even more military scooters.
The National Museum of the US Air Force describes the capabilities of this tough little vehicle:
[...] it had a hitch to pull a model M3A4 general-purpose utility cart. By adding certain equipment, the cart could be converted to carry a .30-cal. or .50-cal. machine gun or an 81mm mortar, though the scooter often could not pull a heavy load. [...] Cushman made nearly 5,000 airborne scooters for the military beginning in 1944. The rugged, simple Model 53 could travel through a foot of water, climb a 25 percent grade and had a range of about 100 miles.
A surviving example of the Cushman airborne scooter was once featured on the reality TV show Pawn Stars.
-via David Burge | Photo: War History Online
P.S. Check out the French Army's anti-tank Vespa.