The sliding block puzzle on this photo was invented by James W. Stephens; it is called the simplicity puzzle. The aim is to move the three square piece from the bottom right corner to the upper left corner. My colleague Edwin Santing produced it using the 3D printing facilities at shapeways.com, and google sketchup for the design.
Mike W. Stephens has his own puzzle site, called puzzlebeast. He specializes in sliding block puzzles, and his site is well worth a visit.
Beautiful as this puzzle is made, it is easy to make a temporary one yourself from cardboard. There are many, many shunting puzzles possible, and I intend to get back on this topic later.