Along the lines of the cool LED matrix animation editor a few posts below, I came up with a way to simulate 8x8, 16x16, 32x32 LED displays so I could write maze processing code while on the road and not connected to any electronics.
Blogged about it with all the code at Arduino: Windows simulator of driving matrices of 8x8 LED arrays. It allows you to move around in the 'maze', switch display modes between static and scrolling mazes, and flip between 8x8, 16x16, and 32x32. The maze class is self-contained and you ask it for what to display at each LED position - so the maze class can easily be dropped into Arduino code instead of the simualtor - the whole point of developing the simulator.
Hope it's useful to someone.