I have recently signed up to a beta program with O'Reilly publishing. You soon will be able to automatically sync your purchases directly in to a folder within Dropbox (/Apps/O'Reilly Media). I always buy books direct from O'Reilly rather than from Amazon etc, you can read my reasons why here.
Like I said it is currently being tested, there is a tentative date for it to go live at the end of June. As soon as it is live I will post an update.
I always used to download my books to dropbox, but it was always a manual process, Create a folder, download a copy of each format I wanted etc, well now you have one button to press.
You can configure your format preferences in your personal info, you can see a shot of this below.
Once you have these saved then from now on, when you make a purchase, all you need to do it click "Sync to Dropbox" It creates a folder which is the title of the book, then automatically downloads all the formats for you.
Once you press sync to dropbox, you get a nice informative couple of alerts.
I bought the book above to test this out, and it has worked perfectly. You can also go into "Your Account" and sync your past purchases as well, which I have done on some other recently purchased books. Before as I mentioned it would be a folder called Python or Linux and I will copy my books into those directories so they are grouped. I prefer the new method of the book title being the folder name with all the formats, and a bonus as you don't have to type them out.
This feature will be very handy when updates are published, now when you get the email saying there is an update, one button press and you will have all the formats updated.
I am always interested in your thoughts so if you have any comments or feedback then please feel free to add any comments, or you can mail me here.
This is now LIVE and available for everybody :-)
You can see the instructions/FAQ here