I looked in to the whole DRM removal thing. From what I could tell, everything was majorly out of date, required a really old version of Calibre, and didn't work with newer books.
Edit: So, this is out of date info. There's a fork and it works with a fairly recent version of the PC app. Basically no fuss.
Yep, looked it up again today and some proper information has been posted publicly in the interim since I last tried. I was able to strip the drm from a handful of my books today using it and an older version of the Kindle PC app.