I'm watching this on Eurosport at the moment, Brazil vs Japan is currently on. In my ignorance I have never watched this before, but I can now see why it's touted as the future of developing young footballers. There's no advantage in being big and strong or playing hoofball. Encourages precision when kicking the ball, as the ball is so small any miss-kick is punished. Encourages quick passes and the use of both feet as you get no time on the ball. The above factors mean it'll never catch on over here, the parents shouting "get it up there" will hate it! Give it a watch if your bored!
Love this game. Watched hours of it a few years ago and even introduced a team tournament at my school at the time. Fantastic game, really difficult but rather enjoyable.
It's good fun with some slightly weird rules. If you concede five fouls the opponent automatically gets a "long penalty", or something like that. And a red card only reduces your team's numbers for a couple of minutes, before you can bring a sub on. Happily highlights of the tournament are on the FIFA website - http://www.fifa.com/futsalworldcup/index.html. Usually teams will do well to score more than about eight goals, but at the last tournament Russia beat the Solomon Islands 31-2.
I play it, great little game it is, you have to be pretty technical to play it, but it's a great game though, very little "hoofball" involved in it.