http://www.amazon.com/gp/help/customer/ ... =200767340
Here's the basic description:
Kindle Personal Documents service makes it easy to take your personal documents with you, eliminating the need to print. With Kindle's Personal Document Service you and your approved contacts can send personal documents wirelessly to your Kindle, archive them in your Kindle library and download them any time you have a wireless connection. You can create notes, highlights and bookmarks on your personal documents and they will be automatically synced along with the last page read across various multiple Kindle devices using Amazon's Whispersync technology. The Kindle Personal Document service is not currently supported on free Kindle Reading Applications.
If you own a Kindle device (for now, not an app), you can now mark up your own documents with notes and highlights just like you have always been able to do with ebooks purchased from Amazon. Those markups are then stored with the document by Amazon and can synched to other Kindle devices you own. You can read something you're writing on the go with your Kindle, mark it up, and then incorporate those changes the next time you're back at your Mac. For now, you'll have to view the changes on your Kindle. Sometime in the future, you should be able to view the markup on a Mac Kindle app.
Exchanging documents with others for proofing and detailed, insert-a-note-here manuscript advice isn't there yet. Authorize each others' email addresses, and you should be able to exchange manuscripts with someone, placing it directly on their Kindle. But as far as I can tell, there's no way, apart perhaps from some hack, to get this second person's markup into your account as if you'd made that markup. It simply becomes one of his personal documents in his account. Perhaps in the future Amazon will allow linking between Kindle accounts, so mark up on one appears in the same document in in other Amazon user's account. That's what they are already doing with public sharing of markup. This would just make that sharing available to a select circle.
Of course, even with this limitation, that still makes this Personal Documents Service an easy way to proof your manuscripts without killing trees. It is also a great way to share your book-in-progress with friends. They can read what you've written and offer advice via email or phone.
Feel free to share in this posting any suggestions you have for using a Kindle to make the writing process easier and more effective.
--Michael W. Perry, Untangling Tolkien