Non DRM Mobipocket format is already supported on the Kindle - just drag and drop.
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.
The Kindle has a built in cell receiver so that you can wirelessly browse, preview and purchase books using one-click.
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.