I bought one of these a few years ago while visiting a resort in Japan. they had them in the rooms and I got hooked. Though haven't used it recently I managed to get maybe half way through the puzzles they had listed. It can be adictive.
It definitly is.. I started making a set for my cousins birthday, he likes puzzles alot. I'm making them out of different scrap pieces of wood (marple, white oak, mahogany, pine & walnut) and sprayed over with a non-toxic varnish so he can bite them as much as he wants =) (he's 2 1/2)
Where now the horse and the rider? Where is the horn that was blowing? Where is the helm and the hauberk, and the bright hair flowing? Where is the hand on the harpstring, and the red fire glowing? Where is the spring and the harvest and the tall corn growing? They have passed like rain on the mountain, like a wind in the meadow The days have gone down in the West behind the hills into shadow Who shall gather the smoke of the dead wood burning Or behold the flowing years from the Sea returning? ~ J.R.R. Tolkien