As any one interested in game AI, I have also implemented the famous A* algorithm for finding the shortest path.
In the demo I made you draw a picture and click on a start and an end point then you get to see the algorithm searching a path between the two. It is possible to vary how many cells to open in every frame update, thereby scaling the animation speed. This can also be useful in games to distribute the path finding cost over several frames.
For curiosity: The algorithm is showed above working on a 2D, templated grid data structure where each cell is a UI Element made in my ProgUI framework. By right clicking cells you set a property saying that the cell is blocked and this can be cleared with the middle button.