If you feel weirdly disconnected from your Facebook profile when you're not logged in, try out the new Facebook Messenger application, which is available for Windows now. The new app follows the mobile Facebook Messenger applications released last year, and an a version for OS X is reportedly on the way as well.
Facebook Messenger for Windows allows you to send and receive chats from a standalone application rather than needing to have Facebook actually open in a browser to chat. The app also provides you with instant notifications about comments, photo tags, etc, as well as displaying your Facebook News Feed. Facebook Messenger doesn't yet have the Skype video chat features that are available when you're actually logged into Facebook, but we'd expect them in the future. The Verge reports that an OS X version is also on the way, but there's no timeline for when it will be available.
Tons of people use Twitter almost exclusively through standalone applications on their desktops, and while Facebook integrates into some of these applications, like TweetDeck, the social network has been sorely missing an app that can keep users connected when they're not on the web. Whether or not the app will help Facebook replace AIM as the goto standard for desktop chatting -- we'll just have to wait and see. [Facebook via The Verge]