Users are able to get their hands on the latest Facebook 3.0 application for the iPhone a little early, directly from Apple via the AppStore. The application is believed to be in the final stages of approval, moving from Apple's review process to the App Store.
The new release brings an updated UI for Facebook, offering new features, smoother and faster load times, the ability to handle events, view pages, and also an updated Facebook chat for instant messaging conversations. Additionally, Facebook 3.0 also offers users the ability to "Like" a friend's status, a feature that was not available in the 2.5 release.
In order for users to receive the early update, users must first delete their existing installation of Facebook off their iPhone, done by simply holding down on the Facebook app and pressing the "X" button. Once the application is removed, load up the App Store and download Facebook again. The App Store will still display the latest version as 2.5, but users will receive the latest 3.0 installation.
Update: The 3.0 upgrade is now fully published to the App Store so you should not need to remove the existing installation to see the update.