We did stringing the popcorn and cranberries...boy, that popcorn was more difficult than I thought to string. Next year, I will let it get stale before I string it. It was too breakable. Cranberries were fun, though.
Other ideas.....gingerbread houses are fun (my mom does it with all the grandkids, but if she didn't I would do it with my son), christmas songs/cds, pack hot cocoa and drive around to look at christmas lights, make christmas cards, go to some of the christmas shows in your area, watch the christmas shows on tv, read christmas stories like the Twas the Night Before Christmas (one per night the week before Christmas), stencil and spray snow on the windows, make homeade christmas gifts (ideas on the internet, magazines, library books, etc.), cut snowflakes, make snow angels, sled, snowmen, ....