We've taken to leaving a "coin jar" on our kitchen counter, and my husband and I occasionally have a cleanout  (cars, wallets, bags, pockets, purses).  If you're anything like me, you're wondering why your purse/diaper bag has suddenly gotten so heavy only to find a pound of loose change floating around in there.  When the coin jar reaches a certain point, I cart it off to the grocery store with me to be counted in the Coinstar machine.  Even with the few cents off per dollar for the counting, I can get an easy $10-$20 or more off the grocery bill with this "found money" that was just rolling about the house.  Check out their website for more information or to find the Coinstar machine nearest you.