Common Symbols and Their Meaning

Cheetah - Speed
Cupid Heart - Love
Horseshoes - Luck
Dove - Peace
Uncle Sam - USA
Hat and Wand - Magic
Horseshoes are considered a good luck charm in many cultures. The shape, fabrication, placement, and manner of sourcing are all important. A common tradition is that if a horseshoe is hung on a door with the two ends pointing up then good luck will occur. However, if the two ends point downwards then bad luck will occur. Traditions do differ on this point, though. In some cultures, the horseshoe is hung points down (so the luck pours onto you); in others, it is hung points up (so the luck doesn't fall out); still in others it doesn't matter so long as the horseshoe has been used (not new), was found (not purchased), and can be touched. In all traditions, luck is contained in the shoe and can pour out through the ends.
In some traditions, any good or bad luck achieved will only occur to the owner of the horseshoe, not the person who hangs it up. Therefore, if the horseshoe was stolen, borrowed or even just found then the owner, not the person who found or stole the horseshoe will get any good or bad luck. Other traditions require that the horseshoe be found to be effective.
One reputed origin of the tradition of lucky horseshoes is the story of Saint Dunstan and the Devil. Dunstan, who would become the Archbishop of Canterbury in AD 959, was a blacksmith by trade. The story relates that he once nailed a horseshoe to the Devil's hoof when he was asked to reshoe the Devil's horse. This caused the Devil great pain, and Dunstan only agreed to remove the shoe and release the Devil after the Devil promised never to enter a place where a horseshoe is hung over the door.
Also some believe that if guests come to a house where a horseshoe is above the door. If they enter through that door they must leave the same way or they will take the luck from the horseshoe with them from your house.