People who don't pick up the coin if it's dirty: you need to think about the people who pick it up even if it is dirty. All your money is filthy; it's been handled by countless people.

I don't pick up pennies because it's not worth my time. A dime though, watch out! :)

Pennies are cool because they depict Lincoln on them. If only for that reason, I hoard all pennies like Donkey Kong does with bananas.