My brother and I have found hundreds of dollars in change in Coinstars, vending machines, etc. We lived in CA for a year and people there seemed too careless about their money. Once we found 298 pennies, 1 dime and a quarter in the reject bin of a coinstar! We had to fill our pockets full and keep our pants from sagging down!
We also found a $20 in an ATM and a $10 under a self serve cashier in Home Depot. Many times I have also found $1s AND $5s on the ground.