Thanks to several of my students, past and present, for introducing me to some of these purely free, fun things you can do with Google. Try these out! 

1. Go to goglogo.com and type in your name to make a personalized search engine
2. Go to google.com, type in no gravity, and click "I'm Feeling Lucky"
3. Play Pacman for free -   https://www.google.com/doodles/30th-anniversary-of-pac-man