This is an impressive startup company that's developing software which allows you to copy the voice of anyone by feeding the system a 1 minute recording of them. Lyrebird compresses his or her voice into a unique key, which can be used to generate any sentence you wish. The product is not available on the market as of this posting, but check out the demos on the site for some cool examples.
Draw a terrible doodle and let Google's AI try to guess what it is. This Pictionary-like game is built with machine learning. You draw, and a neural network tries to guess what you’re drawing. The more you play with it, the more it will learn. This is an example of how you can use machine learning in fun ways.