Do you have an answering machine or service for your home?
Why not get really silly and record a festive message! (It may help remind people that it will be Christmas soon....)
* sing a song (just the chorus will do)
* put on a pretend voice and introduce yourself as Santa, Jesus or the Christmas fairy from on top of the tree, just standing in for the usual answering service....
* get the kids to say something Christmas-like (not what they'd like as a present!)
* play a song in the back ground (quietly) and say your message.