I found this awesome little program that acts as an active background or screensaver looks just like the Matrix code in the movie! Unlike many of the other screensavers out there, this program is fully customizable! You can choose the font, color, speed, text and even integrate hidden messages in the code!
The program is called ZMatrix and can be found at http://zmatrix.sourceforge.net/. You should give this a try, it simply looks stunning!