Here are a few links to some of the interesting ideas out there. Views expressed are those of the authors.
The Jesus Puzzle - Did Jesus walk the Earth? Analyzing the new testament through the lens of a classicist, Earl Doherty concludes that the Jesus of Paul and the 1st century Christians was purely a being of spirit, and had little to do with the teacher and healer character who later appears, as a literary device, in the gospels. You've really got to read through the site, or at least the condensed article, to get the full picture.
I see no conflict between this possibility and Christian faith. Clearly it does conflict with literal interpretations of the Bible and important doctrines of many churches. It also conflicts with popular notions of Jesus as a fully human teacher, prophet, healer, seeker, and/or social activist.
Myself I like the fully mythical Jesus. He is freed from the constraints of time, geography, and politics. He becomes like a pagan god, both more universal and more personal than the church version. I don't think this is Doherty's intention, but this makes me much more likely to consider myself Christian (though not exclusively so). I like to think Joseph Campbell would agree.
36 Arguments for the Existence of God - excerpts from the novel by Rebecca Goldstein - scroll down to the appendix for the arguments with rebuttal. Conclusion: you can't logically prove the deity's existence. (Nor can you disprove it.)
Godhead Trilogy by James Morrow - a great series in the genre of fantasy fiction. Takes Nietzsche at his word that "God is dead," and follows the idea to absurd lengths and profound philosophical depths.
Why a Scientist Believes in God - with rebuttals. This old chestnut has been making the rounds on the internet thanks to the popularity of "intelligent design."
Church of the Flying Spaghetti Monster - a brilliant rebuttal to the push to teach "intelligent design" as a scientific theory in schools.