The Kindle only allows the reading of Amazon DRM-protected content. So how do you load other eBooks onto the Kindle?  Just convert other ebook to PDF.

That’s one solution that upload Mobipocket books onto his Kindle.  Mobipocket Converter, that’s able to convert eBook files to PDF format,   it is very easy to do,  now you can do that too, download Moibepocket Converter at here.  you should feel good about reading your non-Amazon eBooks on the Kindle.