I've been using the hardcover 3rd edition for a while now and absolutely love it. I recently purchased a Kindle DX and think it would be fantastic to carry around the PDF version of the book on my Kindle. I'd like to buy a subscription to the electronic version of the book, but I'm not sure if encrypted PDFs are supported on the Kindle. Is there any way to get this to work?

Alas, this doesn't appear to be technically feasible right now. We are always hoping that future platforms will allow us new ways to sell copies of NR3 :)
Cheers,
Bill P.