Another site, the non-profit Kiva.org, is also social in nature, but instead of donations to charities, it lets you make interest-free loans to entrepreneurs in developing countries.

CNN: Social networking adds new friend: Philanthropy

"The abuse of prescription medications is one of the most troubling public health problems in our country today, " said Steve Pasierb, president of the non-profit Drugfree.org which runs education campaigns about drug abuse.

BBC: US to target fake online pill pedlars

When America goes to the polls in November, every voter in New Jersey, Maryland, Delaware, South Carolina, Georgia and Louisiana will use the same direct response electronic (DRE) voting machines that lack any paper backup and have been shown again and again to suffer from security flaws, according to polling place data gathered by the non-profit VerifiedVoting.org.

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