Grant Thompson of The King Of Random explains the popular web trick of ice bending.

Simply freeze bottles of purified water in your freezer for just under 3 hours. The water will be at the freezing point, but won’t be exactly crystallized. Then, by just tapping on the bottle, the crystallization process instantly occurs. 

This is actually the same secret used for China’s slushy frozen Coke



Update: You can use the trick to make a homemade slushy!