Santa without a Fireplace
How many times have you heard some small child ask how Santa can get into the house if they have no fireplace? The parent usually mumbles something incomprehensible before just saying it's magic. That's a pretty lame explanation. There's a better one.
Ok, so magic is still involved, but more detail really helps the kid. Here's how it happens.
Santa has a large group of specially trained elves who sneak into people's houses and building fireplaces and chimneys. Once they finish the brickwork, Santa comes in, does his business, and takes off. After that, the elves disassemble the fireplace and use the materials at the next house.
Most of the time, this will settle the kid on the matter. But wait, there's more. Now you have to prepare for the next step. This is the part that will not only completely seal the image in the kid's imagination, but will greatly increase the likelihood that the kid will need therapy as an adult.
Go to your favorite building supply store (or unguarded construction site) and get yourself a brick. Make sure the brick is fairly clean; you don't want any asbestos or other bad chemicals on it. It will help if your brick has a little mortar stuck to it to give it the used look. For bonus points, carve into the brick so it says it comes from the North Pole Brick Works.
On Christmas morning, the kids will run to find what Santa brought them. Imagine their sense of wonder when they find a piece of brick that the elves left behind. They will totally believe that elves broke into your house and built a fireplace for Santa.
If you really want to sell this, make some cardboard templates. One will be in the shape that the fireplace would have taken in the room where your tree resides. The others will be in the form of footprints, at least Santa-sized, but you can include some elf-sized footprints too. Use flour to dust around the templates to leave prints on the floor. That will really freak the kids out.
If you can do this, your kids will no longer wonder how Santa gets in with no fireplace. Of course, the kid may become extremely paranoid about the way elves can get into the house at any time and do whatever they want. That's a small price to pay to give a kid a sense of magic.