Circulating (using) the penny and nickel COST American taxpayers money -- twice as much to produce as their value!
Further, they are both nearly worthless, annoyingly heavy (nickels), and slow down supermarket checkout lines. Let's be smart enough to recognize they're basically obsolete and make a move to improve the system!
Canada has already seen the light and banned the penny -- let's one-up them by taking the next step and getting rid of the nickel, too. There are better uses for those materials.
During an era of efforts to be economically (& environmentally) sustainable, it is utterly wasteful to continue producing and circulating these "precious" metals -- it's just common cents.
Additional info:
http://en.wikipedia.org/wiki/Penny_debate_in_the_United_States