Pennies would be fine if they didn't cost taxpayers over $100 million to mint every year. Or maybe if you could buy anything at all for $.01. But you can't.
Pennies are useless, and the only reason we have them around is because we've been too lazy to bother getting rid of them yet.
Our enlightened neighbors to the north, the Canadians, got rid of the penny and haven't looked back. It's high time that we join them.