The magician has a quarter and a soda bottle with an opening too small to accommodate a quarter. With a quick movement, the magician slams the quarter into the bottle's opening, and the quarter appears in the bottle. The bottle is then returned to the store for the deposit.
There are many gimmicky ways to perform this trick, using rubber bottles or bottles that have secret hinges. But these gimmicks are not at all necessary. The fact is that although a quarter will not fit in the opening on a soda bottle if you try and put it straight in, it will in fact exactly fit if pushed through the opening at just the right angle. If you spend a little time with a coin and a bottle, you should be able to find the precise angle without too much difficulty.