I spent time surfing around online yesterday, and have also been reading Richard Dawkins' The God Delusion. Dawkins is a vaguely militant atheist, but upon reading his book and thinking about what he has to say, I would say his skepticism trumps his atheism, and I think it's important, as he does, to make a clear distinction.
If I understand Dawkins' argument clearly, scientifically well-founded skepticism disallows a 100% atheism, but inevitably leads to a 99.99% atheism. But a skeptic will always say: "show me the evidence, and I will change my mind." A 100% atheist will affirm that no evidence will ever be found: that's what I like to call "faith-based atheism."
My wanderings online led me to wikipedia (inevitably) where I found an article on mereological nihilism. As I have understood it, it's a sort of extreme anti-platonism – a denial of the objective reality of all composite objects (which is to say, only philosophically "simple" objects are actually "real" – e.g. quarks and photons and such indivisibles).
Is this a true anti-platonism? Unless I very much misunderstand, it seems an almost perfect inversion of the parable of the cave… In the cave, the "real" reality lies in the transcendent perfect prototypes (i.e. pre-existent images of the compositional objects), and the illusion is in the grainy shadow-projections on the wall. But all these prototypes (categories, or sets, e.g. sets of "simples arranged tablewise" standing for "table") are just illusion under mereological nihilism. I think I may be a mereological nihilist, on top of being a godless atheist and metaskeptic (i.e. I'm skeptical of skepticism). In any event, it sounds cool.