Hey, kids... heard of this Facebook thing that's been hitting the internet? Amazon did! And they're integrating it, along with some newfangled Twitter whatnot, in their Kindle 2.5 software update—along with some other, less-belated goodies.
The full list of enhancements also includes password protection, the ability to pan and zoom PDF files, larger font sizes, and the ability to see what other people have highlighted in the book you're reading. You'll also be able to organize your books and documents into "collections," which sound a whole lot like "folders."
As for Facebook and Twitter, it sounds like you won't be getting a full interface—which, honestly, going through high school crushes' photos in E-Ink would be the only way to make it more sad—but you will be able to share book passages through tweets and updates. Something us friends of Kindle owners are surely looking forward to with bated breath.
The OTA update will start rolling out on a limited basis soon, and you can expect a broad release in late May. [Amazon]