(1) Maybe I'm old-fashioned, but "cool" is kind of a meaningless term to me. Where I come from, we have this saying that "cool" is a word you should use to describe a beverage or the weather, not a person or an idea. It's basically an illusion. If I'm going to lie to my children, it's going to be for a good reason or it's not going to happen.
Wow, some of you people have real issues. And by real issues, I mean you're more than just a little bit baked in the brain. Of course you let them believe in Santa, it won't hurt them. And when they find out he isn't real someday...so what? If this harms your kid, your kid is going to be maladjusted for reasons I won't even begin to explore. Santa is cool. It's that simple. Santa teaches kids that maybe, just maybe, somebody is watching you and maybe you should be nice. Anyone who is/was/will be/or even considers this an act of betrayal, is a fucking nut looking for something to blame their own issues on. Issues that ain't related to Sannnnny Clause.