Since this got resurrected...  The idea is that you could use the interface to send a book to your kindle email address directly.  In this way, I can expose a library to my son via ubooquity, and he can choose to send the book to his kindle -- FROM his kindle (browsing to the ubooquity site).  The kindle itself can't handle the direct download from the site.

Not sure if that made sense, but just trying to explain why it would be useful.  Kindles can browse and (indirectly) download the books all from the kindle; kind of like an alternative "storefront" for getting books onto the kindle.

Along these lines, if you're already implementing the SMTP piece, sending a book from the front end would be helpful. It's not Amazon Kindle-specific (emailing ebooks is handy for everyone), but it would greatly benefit those users.

...but i guess this is what you meant about feature creep ::sorry::