Google has a very strict policy regarding items that can be sold using Google Checkout. Here's what you can't buy:
Body parts - Organs or other body parts
Cable descramblers and black boxes - Devices intended to obtain cable and satellite signals for free
Copyrighted media - Unauthorized copies of books, music, movies, and other licensed or protected materials
Drugs and drug paraphernalia - Illegal drugs and drug accessories, including herbal drugs such as salvia and magic mushrooms
Endangered species - Plants, animals or other organisms (including product derivatives) in danger of extinction
Occult goods - Materials, goods or paraphernalia for use in satanic, sacrificial, or related practices
Prescription drugs or pharmacies - Drugs or other products requiring a prescription by a licensed medical practitioner or any online pharmacies
Weapons - Firearms, ammunition, knives, brass knuckles, gun parts, and other armaments
... and many more.
{ Via Digg. }