Hack let you convert encrypted Mobipocket files that were intended for another reader so that that work on Kindle.
Non DRM Mobipocket format is already supported on the Kindle - just drag and drop.
Non-DRM Mobi books, like free e-books found online in Mobi format, or files you convert to Mobi files, are already supported on Kindle.
There are converters available from Amazon and/or Mobi for pdf and doc files.
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.