To clarify what I am requesting (or dreaming of):
Currently Kindle users can load an app onto their K's from Mobile Read and from Feedbooks that allow users to access these websites and download books directly onto their K's - so that these apps must somehow tweak the Kindle web interface to allow the download of books not purchased through Amazon -- in mobi & prc formats bypassing that pesky Amazon error message denying the download. As many books as you want!
With SugarSync's mobile interface you can access your Sugarsync box via the web interface on the Kindle - but the Kindle is blocking downloads - regardless of the format.
Can one of the existing book download apps be modified for the SugarSync mobile interface to allow direct download of files to the K?