I generated the spherical harmonics images by modifying an OpenGL program that I wrote for Open Day. The code was originally as presented in this workshop. For more information on spherical harmonics, see Paul Bourke's fantastic website. The images in the zip file are print quality and are free for non-commercial use. Please e-mail me if you want to use them for any other purpose.
sphereh.zip (197MB compressed, 648Mb uncompressed, 27 images, 3300x250 Letter size (8.5"x11"@300dpi), 24MB each)