Sadako said:
There are 'Sunday Assemblies' for atheists (a concept which was started by a couple of British comedians), there's the Church of the Flying Spaghetti Monster, there's the followers of the Invisible Pink Unicorn, etc.
Can the Church of the Flying Spaghetti Monster really be considered an atheist church, though? It's a parody religion created to mock Intelligent Design, but you don't have to be an atheist or even an agnostic to do that.