MatrixSaver is a screen saver that replicates the screen effects from The Matrix. The effect is realistic and it works on OS X 10.4 and above although note that OS X 10.4 requires X11 installed to use it. There aren't many preferences but you can change the panning effect amongst a few others. The slight advantage that MatrixSaver has over other similar efforts is that it is fully compatible with Wallsaver which allows you to really impress your friends and use MatrixSaver as your desktop wallpaper so you'll really feel like Neo!
MatrixSaver is a faithful and accurate reproduction of the The Matrix screen effect.