Bellmark is a non-profit organization set up to help schools buy teaching materials and equipment. It was founded in 1960 by Asahi Shimbun newspaper and a wide variety of Japanese companies, including most food companies, support this organization while at the same time receiving positive publicity.
It works as follows: Bellmark symbols are attached to specific products and show how many points that product is worth. Points generally range from 1 to 8, and one point corresponds into one yen's worth of donation. Schools, the PTA or people who support schools clip and collect these marks and then redeem them to receive credits for their school.
One yen per point does not sound like much, but in 2011, roughly 130 million yen was collected. Over 24,800 schools participate, and this includes oversees schools which are recognized by the education ministry. Eighty percent of proceeds go to schools and 20 percent to administrative costs - not bad.
If you have kids in school in Japan, you probably already know about Bellmark, but even if you don't collecting these symbols from packages and giving them to someone who is collecting them might be worth the effort.
The only thing that seems odd is that the technology appears not to have changed since 1960. You still have to cut them off the label, count them up and separate them by company. Sounds like incredibly tedious work which could be greatly simplified by use of bar codes or some similar technology.
List of companies supporting Bellmark and some corresponding products (PDF file)
More detailed list of products with links
Photo is a web capture for explanatory purposes, copyright belongs to the company.