Swim Turtle, Swim
I recently posted a path finding demo that uses a breadth-first algorithm to route a sprite around a map. Kamilche has taken the basic idea and created a new demo with many improvements. Fugu has been replaced with an animated turtle that uses the A* algorithm to do the path finding. A* (pronounced "A star") generally performs better than breadth-first search because it directs the search towards the target, rather than have it expand evenly.
Download Fugu's Friend.Kamilche is the author of Incarnation, an impressive RPG written in Python & PyGame. I highly recommend checking it out!