As people have possibly become aware, pennies are worthless. They cost 1.8 cents to make and do not facilitate the exchange of goods and services. The production of pennies ends up COSTING the federal mint billions of dollars per year.
Please refer to these videos for more information:
http://www.youtube.com/watch?v=y5UT04p5f7U
and
http://www.youtube.com/watch?v=77C47XYm_3c&feature=related