Penny Harvests are run by an organisation called Common Cents. All the one cent pieces (pennies) that are collected are turned into grants for community organizations that help young people do good in their communities. It all grew out of the desire of 4 yr Nora Gross wanting to feed a homeless man in 1991.
As well as what must be millions of pennies, and many other types of coins, there were big dispensers filled with little brown bags for people to start their own collection. Have a look at http://www.commoncents.org/