Amazon has three new ebook readers, and it wants you, current Kindle owner, to upgrade. That's the message behind the latest update to the Kindle Keyboard, which makes it easier to sync and move all your data from your current device. Chief among the new features is Whispersync for personal documents: ebooks, Word docs, text files, photos and more that you emailed to your Kindle or added via USB now get their bookmarks, reading position, and annotations synced across your Kindles. (You can read PDFs on the device, but sadly, they don't get synced.) Personal documents also now live in your online library, where you get 5GB of storage for your documents, instead of them just residing on a single device.
The new features make it trivially easy to buy a new ebook reader and have all your documents, whether you purchased them through the Kindle store or you added them yourself, available and up to date — it's a smart, sly move from Amazon. Version 3.3 also brings AmazonLocal deals if you bought the "with special offers" version, and the Voice Guide shortcut that reads menu options and descriptions aloud. The update should come to your device automatically over Wi-Fi, but you can also hit the source to grab it manually.