Set up tents in the backyard and have a backyard camping trip! Pack up your sleeping bags, fire up the grill, and grab a couple of flashlights and lawn chairs. Don't let anyone back in the house -- except to use the bathroom, of course. And leave your laptops, cell phones and handheld games behind. Remember, you're camping.
For dinner, have a cookout on the grill, and don't forget the s'mores for dessert. Once night sets in, organize some games with the kids. Try flashlight tag, tell ghost stories and even play board games by candlelight. Be creative! If you can, invite some of the neighbors and their kids over to camp as well. The more, the merrier.