Er, obviously Neville is the real Boy Who Lived, but Lord Dumbledore (in a moment of insanity while reading over the draft, I hallucinated a 'Lord' in front of 'Dumbledore', so obviously I had to insert it; those are the rules) made everyone think it was the baby Harry so that Voldemort would keep trying to kill the wrong person.

See, in your ridiculousness, you've quite possibly come up with the best theory ever. (And yes, really, why couldn't Harry's ability to speak Parseltongue just be...because?)