Cascading Matrix style code using Gentoo logo letters with a big Gentoo "G" impression in the code streams.
Aqua versions and other resolutions are also available.
Larger resolutions are over the 500KB upload limit, but they're available on Gentoo's forums (see link below).
***The complete listing***
Green and Aqua versions of 800x600, 1024x768, 1280x1024, 1600x1200.