DRM is not to prevent other files from being readable on the Kindle.
There are converters available from Amazon and/or Mobi for pdf and doc files.
Use Mobipocket software to convert PDFs to that format so you can read them on Kindle.
Think about waiting somewhere in the middle of the day, or perhaps in an airport while you're traveling, and having immediate access to 100,000 books and hundreds of newspapers and periodicals from this pad in your hand.
A revolutionary portable reader that wirelessly downloads books, newspapers, magazines and blogs to a crisp, high-resolution electronic paper display that looks and reads like real paper, even in bright sunlight.