Cartoons on Science
Link to a book which is one of my favorite cartoon books. A lot of science related cartoons which are sure to make you laugh!

Science Cartoons Plus -- The Cartoons of S. Harris
Cartoons available on range of subjects, including science , medicine, psychology, and the environment.

Nearing Zero
An archive of largely satisfactory science cartoon freeware.

Science Cartoons
Science cartoons indexed by category: physics, chemistry, life sciences, medicine, and computers.

Off the Mark-Science Cartoons
Humorous cartoons dealing with all aspects of science.

Tom Swanson's Science Cartoons
Some of these have appeared in Physics Today.

Cartoon Stock
Searchable database of over 60,000 quality gag cartoons and illustrations by the world's best cartoonists.

Science Cartoons - ANDERTOONS
Science cartoons galore! Looking for funny cartoons? Then look no further.

About.com School Clip Art
Clip art for holidays, backgrounds, icons, photo clips, buttons, bars, special occasion clip art, etc.

Discovery School Clip Art
Choose from hundreds of original clip art pieces, including animations!

Science Clip Art, Illustrations and Pictures
Classroom Clip art: Over 30000 free Clip Art images, illustrations and photographs in over 650 categories.