This thread is understandably long, so i won't pretend i've read past the first ten or so posts.
However, I was watching, ok half watching that thing about the Old Testament last night, with the greek Dr with the huge boobs (dh always insists on watching for some reason, but i think she looks a bit like Sacha Baron Cohen. anyway...), and she put forward a very convincing argument for God's non-existence. Dont' know if anyone else has mentioned this yet, but to summarise:
Judaism is what Christianity and Islam rely on for their tradition of monotheism. In order to do this, all three religions point to old testament 'proofs' that there is only one, omnipotent God. However, if you actually study the original hebrew, it doesn't take long before you find scholars referring to God by the old Caananite names (the pagan gods so reviled by old testament prophets).
In fact the names are used interchangably; you can almost see an evolution of the idea of what God is: attributes formerly ascribed to male and female goddesses get absorbed into the character of 'the almighty', who himself seems to have evolved from the idea of 'El' or the father of the Canaanite gods. This idea that the Israelites, who founded all three monotheistic faiths worshipped only the one true god starts to seem quite laughable.