How do you load other eBooks onto the Kindle? Just add Amazon DRM.
Granted the PDF converter seems to have some trouble with graphics PDF's, but for books the converter works very well.
Hacker Igor Skochinsky used DRM to load Mobipocket books onto his Kindle. Using a series of scripts, he's able to convert eBook files to Amazon's AZW format and then add the necessary serial number DRM, specialized per an individual's particular Kindle.
There are converters available from Amazon and/or Mobi for pdf and doc files.
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