http://www.johnrausch.com/SlidingBlockPuzzles/Default.htm
Here you will find a good amount of sliding block puzzles ready for you to play from the computer, from recreations of wooden classics to modern designs. There are so many and so varied as to dare to say that they’ll keep you frustrated entertained for a very long time.
On the same topic, www.johnrausch.com/ offers links to several other puzzle-themed sites, covering all sorts of details from books to craftspeople. Loosely related to the sliding block puzzles, you shouldn’t miss the boxes designed by Yoshio Okiyama, most likely impossible to open even with instructions, or a heart-shaped “Love Box“, very appropriate for Valentine’s Day.