Useful, at least for those of us with an accumulation of O'Reilly ebooks ...
"You can now automatically sync all your ebooks with your Dropbox* account. This is a new feature we're beta testing. Just log into Your Account, click the "Personal Info" tab, and authorize syncing with Dropbox."
• Syncing large libraries can take as long as half-an-hour. All products might not sync to your Dropbox account when using the "Sync Ebooks to Dropbox" button. Please try again or sync products individually.
• Verify the size of your Dropbox account before syncing. Free accounts have limits.
Note that O'Reilly (http://oreilly.com) has been adding other publishers' titles to their on-line store of DRM-free (available in multiple format) ebooks.
Today, they've just added 3,000 more titles from Wiley (various books with the Wiley, Sybex, Wrox, and "For Dummies" imprints).
Nice for us who like to see technical books of interest being offered as ebooks that we can read on multiple devices rather than getting locked into a Kindle, Nook, or iBooks via DRM.