I'm with pretty much everyone else on this -- not so great for a ball, but freakin' awesome idea for a carpet. I just might have to steal this idea in the future as I wanted to build a large corner display enclosure when I finally get a carpet. This idea should make the whole thing a lot easier to build, and if you put a false floor under it you could actually make the drain functional. How easy would cleaning it be if you can just go in there and hose it down?