I've long entertained a dubious regard for the practice of lying to children about the existence of Santa Claus. Parents might claim that it serves to make children's lives more magical and exciting, but as a general rule, children are adequately equipped to create fantasies of their own without their parents' intervention. The two reasons I suspect rest at the bottom line are adherence to tradition, and finding it cute to see one's children believing ridiculous things.
Personally, I considered this to be a rather indecent way to treat one's own children, and have sometimes wondered whether a large proportion of conspiracy theorists owe their origins to the realization that practically all the adults in the country really are conspiring to deceive children for no tangible benefit. However, since I began frequenting this site, I've been exposed to the alternate viewpoint that this realization may be good for developing rationalists, because it provides children with the experience of discovering that they hold beliefs which are wrong and absurd, and that they must reject them.
So, how did the Santa deception affect you personally? How do you think your life might have been different without it? If your parents didn't do it to you, what are your impressions on the experience of not being lied to when most other children are?
Also, I promise to upvote anyone who links to an easy to register for community of conspiracy theorists where they would not be averse to being asked the same question.
I'm struggling with this myself right now.
I've long had the idea that, if I ever raised a child from a young age, I'd introduce Santa Claus as a make-believe game. I might be a little coy about it: tell the story of Santa and see if the kid can figure out the truth without giving a direct answer one way or the other; but I wouldn't lie. OK, there's a plan, but it's all theory, since I'll probably never raise a child.
But now I'm dating the single parent of a six-year-old. She is raising her child to believe in both Santa and Jesus; she herself knows the truth about Santa but still believes in Jesus. One the one hand, I've played the Tooth Fairy for the child; I removed the tooth from her pillow and put quarters under it, at her parent's request. On the other hand, I told her —in response to a direct question— that I don't believe in Jesus. (Then she asked me if I understood that I have to accept Jesus to go to Heaven, and her mother gave her a lecture on tolerance, in the course of which we learnt that not everything taught at her Christian elementary school is necessarily correct, so that was good.)
I am not raising this child, and her mother and I have such different views on how to do so (Santa, and even Jesus, hardly even begin to cover it) that I have decided not to make any effort to even help to raise her. (ETA: Not that I've been asked to, but I have my answer if I ever am asked.) I am her friend and occasionally her baby sitter, but I am not her parent and probably never will be (and certainly never will be without a long discussion about it, some years into the future).
Still, if she asks me a direct question about Santa, then I'm not sure how I'll answer it.
I would suggest you be a good skeptic and answer the question about Santa Claus the same way you answered the question about Jesus: that you don't believe in him. Note this isn't the same as saying he doesn't exist, as this would be stating as fact that which is only highly probable.