60 mins

http://freakonomics.blogs.nytimes.com/2008/02/07/a-penny-for-your-thoughts-what-an-insult/

Nobody on here used the argument that pennies are a diet pill. They cost more calories to carry around than to spend on food. Which might make for an interesting social cost. But in any case, I hate pennies. And would welcome the capacity to do this:
"remember when it was introduced some wags did things like go to the supermarket and buy a bunch of fruit or veggies one piece at a time. Like put each grape or mushroom through and it gets rounded down to nothing and is free. Do that over and over and you get a whole bunch/bag free.". I think that would be fun, once or twice. It'd be easy to do late at night through the self-checkout lanes I should think.
In any case, with currency rapidly being removed in favor of electronic spending, a movement to remove the actual and truly useless currencies is long overdue. The idea that I have to carry around 2 or 3 pennies with me all the time to avoid getting more of them when I spend cash is ridiculous. 4 pennies is a true waste, you only get one back, why bother unless you have jars and jars of the things at home. Find something else to put Lincoln's face on and be done with it.