While an uncircumcised penis leaves more for a man (and his partner) to play with, a new study confirms that circumcision reduces the chance of infection from HIV, HPV and Herpes-2.  

A study published today in the New England Journal of Medicine examined the occurrence of syphilis, herpes simplex virus type 2 (HSV-2) and human papilloma virus (HPV) in both circumcised and uncircumcised men in Africa. After two years, it found that circumcised men had a 25 percent reduced risk of infection of HSV-2 and a 35 percent reduced risk of infection of HPV.  Syphilis showed no difference. Previous research found that circumcision may reduce the risk of HIV transmission by 60 percent.  The results are said to be generalizable to American men, yet the study is not without its caveats. To read the details, check out the New York Times article about it.  Also, here’s the abstract to the study.