Has anyone ever used a balance board in training. I have been told that some goalie coaches have their students use them. The only one I have been able to find is at http://www.indoboard.com/ and I am not sure if this is the same balance board as is used in training. I am considering getting one of these for both my younger son who plays goal and my older son who is a center. It looks like it's fun and it would be great if it really does help develope better balance. Does anyone have any experience with ones of these things or know of something better?