All,
I am sure the majority of you enjoy good brain teasers and puzzles. A few years ago, I received a wooden puzzle for Christmas that apparently can be solved in as few as 16 moves (unverified). I have never came close and wanted to see if my fellow monks were up to the challenge.

This is a picture of the starting position. The object of the game is to get the large square (red dot) to the position at the bottom occupied by the 4 small squares (blue dots). You may only move pieces by sliding them.

The challenge is to write a program that will solve the puzzle in the fewest number of moves possible. Graphic solutions are not necessary, but would be cool. Any solution method will be eligible (golfed, regex, bruteforce, etc). The solution must be able to be verified using the real puzzle :-)

The story behind the Setting Sun Puzzle can be found here

Update: It is definately not 16 moves as this site would suggest. The 16 step solution (don't peek) requires multiple moves to get to each step. My definition of "move" remains and the solution with the fewest moves still wins.