The Soviet Teletanks were the world's first operational remote-controlled war machines put to use during WW2. They were initially based on the French FT light tank series that experimented with post-WW1 crowd control tanks that were remote-controlled and had a large mast attached to them with searchlights to patrol at night. The Soviet versions were varied but used basically the same TOZ-IV telemetric system in which one control tank operated another unmanned armed with light MGs, flamethrowers, smoke canisters, or HE loads for dropping- in pairs. The first TTs were used against Finland in 1940 during the Winter War. The Finns knocked them out. By the time Germany invaded the USSR in 1941 there were three models: TT-18, TT-26, and a few TT-34. At Kursk it is claimed that TT-34s were thrown into the mix although there is no real photographic proof and the Tigers probably could not tell the difference anyway at such long ranges when they took them out or the control tanks! No further use after Kursk. The Germans used remote-controlled tanks too, but on a different scale. The Goliath "mini-tank" was a demolition vehicle primarily as were the B-IV series. Both types carried explosives and operated as engineering "carriers". Sometimes a Goliath could approach a single Soviet tank undetected until the machine gunner spotted it. This was due to its ultra-low profile. Again, postwar, the concept was experimented with but found to be a dead-end of unreliability and prone to jamming. The latest incarnations are ACRs (Autonomous Combat Robots) with very sophisticated computing tech. There are many armed robots testing right now but Germany has a automated light tank in the airborne Wiesel which can be armed with a 20mm cannon, a 30mm recoilless gun, or AT missile launcher. It has not been used in combat. Another German wonder is TeleMAX which is a crane panzer automaton for police and military use. Currently, it is under development.

TT-26 taken out by Finns in Winter War: http://upload.wikimedia.org/wikipedia/commons/thumb/4/4b/Tt-26.jpg/479px-Tt-26.jpg German Goliath: http://4.bp.blogspot.com/_CbwnjooteyI/SAy-tpxPmnI/AAAAAAAAJJI/UHPOnXgV3G4/s400/goliath_1.jpg