I know in most houses there are little cups of coins lying around the house, and our house is no exception. We had about 10 years worth of change sitting in tubs, so as part of my spring cleaning process I sat down with the kids and we sorted the change into separate denominations in small zip lock bags bags. The kids have been sick this week, so it was a nice quiet activity for them (just be careful of small children sucking the money).
We then went to the bank and watched the teller weigh the money to add it up, and deposit into our account.
It is a good activity for teaching children about the basics of money, counting and categorising.