awesome dupe trick:

[T7g]

I remember when I was in South Carolina one of my cousins showed me a trick with these goofy drink vending machines they had.

Basically it had a glass front and a conveyor belt that moved up and down, and then when at the proper drink it would knock it on to and then would run the conveyor to the left where the drink went through a door and fell out.

All you had to do was reach inside and hold the door that the drinks came through closed, the drink would never register as having been dispensed and it would give you your money back. You'd also already have a drink on the conveyor, so you put your money back in (and do the same thing again if you please) or just select your drink and bam, two come down the conveyor to you.