at some of the mean-spirited comments on this thread.
You see, I wan my kids to be kids for as long as possible. I don't want them to be scared that people are breaking into their house at night. I want them to believe that santa comes down the chimney and drinks the sherry, eats the mince pie and leaves the toys. I was never threatened by this as a child and if my child was threatened by this I would try and find some other way of explaining how the presents got there. Santa is so magical, it makes Christmas for kids. It would be so cruel if I suddenly turned round to them and told them it was all make believe.
Kids work out the truth in their own way. My DSs haven't reached the age of doubt yet but I would just answer their initial queries with "What do you think?" which is how I challenge them when they tell me that so-and-so at school has told them such-and-such. By the time they've worked it out for themselves, they'll be old enough to take it - but christmas will have changed for them, as it always does as you grow up.
I remember one year when I was about 12 my mum decided she would just put our presents in the sack without wrapping them up which was hugely disappointing for me, even at such an advanced age. I was still grateful for the presents but missed the anticipation and the magic of unwrapping them.
And like custy says, we tell lies to our kids all the time, especially about their friends - "Oh no, little Jack didn't mean to be mean and leave you out, he just forgot" when you know for a fact that the evil little shit did mean to upset and exclude him.
I don't spoil my kids. I won't buy them playstations and expensive gadgets that we can't afford and that I don't approve of. I won't let them have TVs in their room or watch 15-rated movies when they're only 6. But I will indulge them in the special magic of Christmas while I can - including the message of Jesus - because all too soon they'll be desperate to get away from home and spend all their time at parties or in the pub. But they'll never forget how magical childhood christmases were, and neither will I.