The Halteres reference article from the English Wikipedia on 24-Jul-2004
(provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Halteres

Have you considered sponsoring a child
Halteres, (singular halter or haltere) from the Greek word for dumbbells, are small knobbed structures homologous to wings and flapped to maintain stability when flying. These specialized organs are found in the place of the forewings of Strepsiptera and the hindwings of Diptera. They act as a balancing and guidance system, helping flies to perform their fast aerial acrobatics.

In ancient Greek sports, halteres were used as lifting weights, and also as weights in their form of the long jump. Their long jump was probably a set of three jumps, and halteres were held in both hands to allow an athlete to jump a greater distance. They may have been dropped after the first or second jump.