Have you seen the new holiday stamps from the US Post Office? They're called Holiday Knits and I keep trying to upload a picture of them but it won't let me. They're sweet, trust me.
Found a cute site that writes personalized letter to your kiddos from Santa. It's free, I printed them out and will pop them in the mail today. I think the kids will get a kick out of it. Here's the URL: http://www.santawritesyou.com