Despite some objections, I support male circumcision -- particularly for those in sub-Saharan Africa. It may or may not save people from being infected by HIV (although some studies say it may have protective effects). The real fact is, developed nations don't supply as much aid to HIV stricken nations as they should. Any prevention strategy that is cost-effective is better than the help that developed nations are providing which isn't even a cure and the aid developed nations provide isn't sufficient to stop the millions of death each year.
From what I remember, circumcision was practiced as a covenant between God and Israel. When I say Israel, I'm basically saying the people of God. If you believe that we are part of Israel, If your are (Jewish/Christian), then you might have to follow circumcision...
In the early days of Christianity there were intense debates regarding circumcised (Jew) and non-circumcised (Gentile) followers of the way, which later on became what we now call Christianity. The debates involved asking whether Gentiles should be circumcised and be allowed into the fold. To cut it short, basically they decided that it was not a requirement of being a Christian. Thus, today Christians are ambivalent with regards to circumcision.
Finally, to answer your question... if I support circumcision... my answer again is yes, for humanitarian and religious purposes. Meaning, I don't support infant circumcision or the like, but support it if the decision is left to the person who wishes to be circumcised.