According to this article in the NYT, “Circumcision appears to reduce a man’s risk of contracting AIDS from heterosexual sex by half, United States government health officials said yesterday, and the directors of the two largest funds for fighting the disease said they would consider paying for circumcisions in high-risk countries.”

I don’t know how valid this is, it certainly doesn’t mean one can have unprotected sex, but it’s interesting, that’s for sure.