You could make a Christmas Tree beanbag toss. Take a large sheet of cardboard, cut it into a tree shape, and cut several holes. Use colorful childrens socks as the beanbags: fill partway with beans or rice and tie closed. Then have the kids toss the "ornaments" at the tree. You could also do "Pin the Ornament on the Tree". Kids love to be spun around blindfolded, heh. Or a Holiday Bingo game.
Easy crafts could be Pasta Angel ornaments. Use the bowtie pasta for wings, the straight tube pasta (I forget the name) for bodies, and small wooden beads for the heads. The kids can have fun painting the angels, and they can either be glued before or after. Hot glue works fastest, but there are some good craft glues that would work too. A tough of glitter will make them really shine. Then the kids can take them home for their own trees.
You could also make Gingerbread ornaments. There are recipes for some that don't need to be baked. Check familyfun.go.com or familycrafts.about.com for lots more ideas.
Have fun!!
J.