Some nice pictures of the moon . You can also get a history of lunar exploration .
the GIMP (general image processing routines) http://www.nuclecu.unam.mx/~federico/gimp/el-the-gimp.html GIMP is on the SOD machines.
Persistence Of Vision(POV-Ray)Trace, create really NICE images http://www.povray.org/
The following two books show some nice graphics based on mathematical models (such as fractals).
Peterson, Ivans, The Mathematical Tourist: snapshots of modern mathematics, W.H.Freeman and Company, New York, 1988.
Pickover, Clifford A.,
Computers, Pattern, Chaos and Beauty:
graphics from an unseen world,
St. Martin's Press, New York, 1990.
ISBN 0-312-06179-X
This book also gives a number of techniques to visualize data so you
can see hidden patterns in the data.
Tufte, Edward, The Visual Display of Quantitative Information, Graphics Press, Cheshire Connecticut.
Tufte, Edward, Envisioning Information, Graphics Press, Cheshire Connecticut, 1990.