1. Sleep
Sleep. Enough said.
2. Doodle or draw
Great people, great minds spent time doodling and drawing im their free time. The doodles of past US presidents, inventors and artists like Da Vinci have become priceless artifacts. Your doodles might become greatly valued to historians or even just to you and your family.
3. Go places on Google maps, street view or Google Earth or maybe even Bing maps!
4. Play an old game (board or video game, etc dust one off, remember the old days)
5. Write in a journal just jot down some thoughts
Well, I hope this little list has been helpful!