9. Read a book (either for/with the kids or by yourself)
10. Take a walk if the weather is decent
11. Go to an indoor play area (even if it's at a restaurant)
12. Go to the library and check out books on an interesting topic. the grammys were yesterday, check out some kid friendly books on music. Make your own instruments and jam out.
13. Have an indoor picnic complete with blanket on the floor and food in a basket.
14. Turn on the "oldies" station and show your kids how you used to dance when you were younger (I say "Oldies" because everything is old to kids - even if it were less than 10 years ago)
15. Make a fort
16. Turn an old box into something: racecar, house, rocket, etc.
17. With your kids, choreograph a routine to show to visitors. This can include tumbling, dancing, whatever your kids can do.