GMAIL: Send a personalized Phone Call from Santa 15 years ago
I have occasionally seen other parents take the Santa thing to the next level with these personalized services. One even paid a Santa to show up on Xmas day. In all cases the questioning and obvious suspicions generated from the kids almost resulted in a backfire. For me it proves Neil De Grasse Tyson's assertion that "children are born scientists". Best not to give them too much evidence to start analyzing.
So if I could offer a piece of unsolicited advice: keep it unreal, magical and mysterious and stick with the whole down-the-chimney thing.