Design a Godless Logo

Now here is a real challenge just waiting to be embraced by the right designer: science blog Pharyngula has highlighted a logo contest to design a symbol for athiests, agnostics and other freethinking non-faithful types. Pharyngula blogmeister PZ says that the cross gives a visual "approximation of the predilections of the owner. Why can't we have something like that?" Some of the ideas that have been proposed so far are featured above. This is an exciting challenge just waiting for some real conceptual muscle—any takers?