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.
The Kindle only allows the reading of Amazon DRM-protected content.
As glued to the net as we all are, there's vast quantities of content that is not available online.
Granted the PDF converter seems to have some trouble with graphics PDF's, but for books the converter works very well.
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.