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It seems like you might be treading on shaky ground there. Rewrites are
necessarily different from original text.
I'd recommend that you find a topic that's short of documentation and write
it. This way, you can come up with "real" writing samples, do a public
service, and learn something cool in the process.
You could write a white paper on XML concepts, with lots of graphics and
diagrams; a tutorial on reading email headers and tracking down spammers; a
guide to writing complaint letters about RBOCs, including applicable
regulations and addresses of Public Utility Commissions*; an overview of
cluster computing technologies; etc.
Make two versions of each: one PDF/paper version formatted for print, and
one HTML and/or online Help version formatted for online viewing. Then,
stick them up on a webpage, linked to your resume.