Contrary to popular believe, Velcro wasn't invented by NASA, but in 1941 by a Swiss engineer who noticed how cockle burrs stuck to his dog's fur.  Did you know that Viagra was invented as a drug to treat Angina...but they found an even more profitable side effect?

Gunpower was discovered in the 9th Century while trying to find an elixir for eternal life.  The amount of everyday items that came about thanks to accidents include microwave ovens, X-Rays, plastic, and Vaseline, just to name a few.

Thanks to the folks at Mental Floss, here are 24 common items that were invented completely by accident.