What turns everything around but doesn't move?

The answer to the riddle "what turns everything around but doesn't move?" is a mirror. Riddles like these are included in many popular games and applications like "What the Riddles" on iTunes.

Riddles are not specific to any one country or culture but are used throughout the world. Archaeologists can trace riddles back thousands of years to temples and caves in the Far East where ancient cultures etched them on the walls. Although some of these etchings included mathematical formulas, many were created purely for fun and entertainment. Some of our modern board games like chess have their root in the art of ancient riddles.