A Green Drinks member mentioned that she did away with her compost pile because she couldn’t stand the flies that hovered around it constantly. I had some time to look into possible fixes for this and found an interesting solution, one that the Discover Channel says has a scientific basis for working: hang plastic bags filled with water – and a penny – where you want the flies to be gone from. The bagged water’s reflection affects flies’ eyesight in an odd way and they don’t want to fly near, so they stay away.
(added 110710) Learned yesterday that a similar recommended technique is to hang CDs so they waft around, floating in the air. Flies apparently also have trouble with the light refraction they disperse.