Who needs stairs? They're so last century. If I had my druthers, going up a floor in a building would be done via escalator, and going down would be done via slide. Giant tube slides, to be exact. You might think it's impractical, but that would just mean that you've murdered your inner child.
The folks at the Tate Modern Art Gallery in London have very healthy inner children, fortunately. They've gone ahead and installed gigantic tube slides that run from the top of the building all the way to the ground floor. When I get around to building my own home, you can bet that I'm gonna be installing something very similar.