I'm sure everyone's had a thought or two about this - what you'd do when (or in most cases, if) you became rich [actually, maybe there should be a suggestion website for what already rich people could do with their money - or is that Harrods.com?].
Given some thought (and excessive richness), one of my more crazy ideas is this:
I'd get a room - possibly the best place would be a work reception - and have a slightly tilted floor descending away from the door. Over the floor would be a custom made shag pile carpet where the shag pile gets thicker (higher) as you walk into it.
The net effect is what looks like a normal level carpeted floor that, as the person walks into it, it gets deeper so you end up wading through it. Most disconcerting but probably very cool ;)
Just a thought!