Is it true the yo-yo was used as a weapon?

Yes, somewhat. It was not the same as today's yo-yo. From http://www.coolquiz.com/trivia/explain/docs/yoyo.asp

"In the Philippines around 1500, the Yo-Yo was a weapon. It consisted of a four pound stone attached to a rope about 20 feet long. Tribesmen used it in two ways. When hunting, they stood off to one side, held one end of the rope and threw the rock towards the legs of an animal. The rope became tangled around the animals legs, and with a tug, the hunter brought the animal down. Against enemies, the stones would be dropped on their heads. The tribesmen would quickly recover the stones, ready for a second blow if necessary."

Talaga!

lol iv never heard that before but it sure makes you think, maybe you cud trip someone up with it, or it cud get wrapped round someones neck, ouch ..

Yes but it was more of a yo than a yoyo as it didn't curl back! :)

Here's an interesting video I found of someone using the yo-yo as a weapon...it's actually quite effective the way they use the string and the axle. They also use a hula hoop as a weapon in the video so it's definitely possible that anything can be adapted into a weapon, or being a weapon in the first place, being used modernly.

http://www.youtube.com/watch?v=Px5Pwg4Bhbw

i have no idea, but Im sure if used with skill, it could be quite lethal !

No! This is a myth. See http://www.yo-yos.net/Yo-yo%20history.htm.

No. The myth of the yo-yo originating from a weapon dates back to about the 1500s in the Philippines, but there is evidence that yo-yos were used by children in ancient Greece and Rome. Plus, the weapon that the yo-yo supposedly comes from is so different; a heavy stone tied to a twenty foot rope. Does that sound like a yo-yo to you? That's as ridiculous as saying gumballs started out as marbles because they are both small, round, and colorful.

If you guys know of the manga Hunter x Hunter, a very good manga :D, Kilua (one of the main character) use metal yo yo infused with eletric! Also in Chinese weaponry, there is the thing name "comet mace" which is a big metal ball attach to a chain or a sturdy string, kinda similar to the Philippine's weapon mentioned above. The reason yo yo is not used as weapon nowadays would probably because it's complication to use.

No.

The yo-yo is often credited as having been a weapon invented in the Philippines a few centuries ago. Despite the popularity of the claim, the idea of Yo-yo as weapon has been denounced by the Filipino American National Historical Society. The idea is also debunked as an urban legend by the chairman of the American Yo-Yo Association’s History and Collecting Committee.

http://en.wikipedia.org/wiki/Yo-yo