I checked online this evening to see if there is any truth to the idea of repelling flies with pennies. Apparently some folks believe that bags of water with a few pennies inside provide a reflective surface that repels the flies. It's on the internet so it must be true.
![Razz :P](./images/smilies/icon_razz.gif)
http://www.snopes.com/critters/wild/flies.asp