awesome dupe trick:

[Lazortag]

1. find a vending machine and put a penny inside
2. push the button that returns your change
3. repeat until a dime comes out

the way the trick works is that sometimes pennies get mistaken for dimes in vending machines. Sometimes you won't get anything back, but it doesn't matter because the trick works more than 10% of the time so you usually end up profiting.