For someone who doesn't believe in the divinity of Jesus, I sure dig Christmas!
One of my favorite modern Christmas traditions is clicking on Leslie Harpold's Advent Calendar. Each day there's a Christmas themed flash thingy or poem and a link to a Christmas memory. Greta especially enjoys the flash games.
Be sure to go to the main site and check out the prior year's calendars as well. They're a real treat.
edited to add: Six days after I posted this, Leslie Harpold died. So sad. She will be missed