The good news is, it's difficult to keep up with all the black freethought activity in cyberspace. Here are a few sites/groups I've recently discovered.
Black Atheists (blog)
"We are a minority within a minority."
Self-contained social network in ning format.
Black Nonbelievers of Atlanta
A local group with a presence on Facebook & elsewhere.
Not surprisingly, these all have the flavor of youth. All seem to be freshly experiencing the vigor and the militancy of self-assertion. Intellectual maturity will take much longer, but clearly there is a tidal wave of nonbelief among young black people in the USA (and elsewhere) that is making its presence felt, weak though in may be in the vast ocean of black religiosity.