Elon Musk is a 39-year-old engineer and serial entrepreneur. At 28, he co-founded the popular e-payment company Paypal. He then went on to start SpaceX, the first private company to launch a rocket into space, and Tesla Motors (no doubt named after inventor Nikola Tesla), which builds electric cars.

Musk sounds like one hell of a rocket scientist. Do listen to the CNN interview with Elon Musk, where he answers the question, "What three inventions will change the world?". And check my profile on Musk, this inventor rocks.  Photo Getty Images

Did you know that the crossword puzzle was initially called word-cross and was diamond shaped? The name later switched to cross-word and then crossword.

According to Interfax News Agency, the world's largest crossword puzzle comprising of more than 64 thousand words was made by hand by a Russian family couple living in the town of Borisoglebsk, Southern Russia. The crossword contains 64,371 words, roughly 10,000 words more than in a crossword by Roger Boucart, a Belgian man who held the previous word record for the largest crossword.

To all whom it may concern: Be it known that I, Elisha Gray, of Chicago, in the County of Cook, and State of Illinois, have invented a new art of transmitting vocal sounds telegraphically...

In the 1870s, two inventors Elisha Gray and Alexander Graham Bell both independently designed devices that could transmit speech electrically (the telephone). Both men rushed their respective designs to the patent office within hours of each other, Alexander Graham Bell patented his telephone first. Photo LOC

• Elisha Gray's Patents
• Alexander Graham Bell's Patent

Did you know that the image of Mickey Mouse is the most reproduced in the world? Over 7,500 items bear his likeness. Jesus is number two, and Elvis is number three. Mickey Mouse's likeness was conceived by Walt Disney himself, who you might be surprised to find out was also an inventor. Walt Disney was granted U.S. patent 2,201,689 for his "art of animation" camera on May 1, 1940. Photo Credit: Getty Images Mickey And Minnie Mouse Welcome Everyone To Hong Kong Disneyland Resort