i shoulda posted this sooner, not sure why i didn't.
anyways, i'm a member of 4 communities on mixi that are relevant. maybe others might be interested.
atheism in general
anti-religious communtiy, anti-cult community
richard dawkins community
the name says it all, "i don't like religion, especially organized religion."
these communities are relatively inactive, but like many communities on mixi, people just join to wear it like a badge to indicate their interests.
if you're interested in science, the richard dawkins community seems like a great launch pad for other science communities (i noticed carl sagan and "meme" and brights communities right off the bat).
if anyone else knows of some other related communities, feel free to post away♪