UPDATE: Here's a run-down of these posts to keep everyone on the same page
elorianne had a post about her problems with the film, Across the Universe - Prudence, Lucy, and several other things - here.
I attempted to explain some of these issues - no constancy, no explanations, etc. - here.
her response to my post, with a focus on Prudence, here.
my hypotheses on Prudence's role in the film, or lack thereof really, here.
It's quite fun, really =)