Not having any children, I've been spared the dilemma of Santa. I've always leaned against it, as I saw no reason to lie to my own children. But I can't say for sure I'd have stuck with that position had I been fortunate enough to have actually fathered some.

Jim H. does bring up an interesting point, though. I can't see "childhood enchantment" being a sufficient reason for perpetuating the myth - at best, it's a selfish reason; it offers no benefit whatsoever to the child, only the parent, knowing of the deception, gets to enjoy said "enchantment." But childhood disenchantment is another matter. As an atheist, the parallels between Santa and God seem all too obvious to me.

How I first knew I was a geek: I discovered Santa was a myth when I first had a chance to study a globe, and realized there was no land at the North Pole! I actually asked Mom whether Santa could be stationed at the South Pole instead, but she was adamant that he was at the North Pole, not the South. I never really trusted her on Santa (or God) again.