Here are some sites that I found with great chemistry cartoons:
Nearing Zero
Mr. Seiler.org
CooperToons
Science Cartoons Plus - S. Harris Chemistry Cartoons
Cartoon Stock
The Cartoon Guide to Chemistry - available for ordering
Cartoonist Group
Mr. Brügge's Eighth Graders

Entertainment and Fun:
Links for Chemists - Topics - Chemical Entertainment and Humor
Other - The Catalysts
Humor - General Chemistry: starting points for students