How does a yo-yo work? asks a reader.Can you Hop the Fence, Milk the Cow, Ride the Horse, and then Walk the Dog -- without ever setting foot on a farm? If so, you're probably familiar with yo-yo ...

It may not be an Olympic sport yet, but yo-yo play is serious business. Especially in Cleveland this week, where the world’s most skilled yo-yo players are gathering for The World Yo-Yo Contest. The ...