Sometime back during the Arifca Campaign, my great uncle was a halftrack machine-gunner. He and his crew were out scouting around the dunes when they saw a Tiger rolling over a nearby hill. They quickly drove back down and miraculously were not discovered as the tank rolled over the dune where they had just been. This sort of event continued several times theoughout the day. Finally, in the evenung they came acrosss a small villiage. As they were turning around a hut, they came across a German tank crew hanging out in front of a completely empty Tiger! My great uncle held them up with the machine gun, his crew called for reinforcements, and hours later they had captured one of the first Tigers in the war! He was offered a Bronze Star but refused to take it because he insisted that he was 'scared shitless' by the whole ordeal - both groups were equally surprised!:D
Not WW2 stuff (except the last one on a longshot), but still good stuff. Captured (and by captured I mean looted) crossbows were used in the first world war by the German Army to lob grenades to the enemy trenches. The saying to keep under ones cap goes back to the longbow when an extra bowstring would be kept under the cap to keep it dry. The V for victory sign is actually a dirivitive of a medieval insult dating back to the Hundred Years War when the French would cut the draw fingers of any longbowmen they captured, so as an insult, whenever the English defeated the French the archers would show their two draw fingers as a taunt.