Facebook today updated its iPhone and iPod touch application [App Store, Free] to Version 3.1, adding highly-anticipated push notifications and the ability to sync Facebook friends with users' address books. Facebook's push notifications offer a fairly high degree of customization, allowing users to choose whether to receive alerts for seven categories of information.
Push notifications had been on many users' wish lists for the 3.0 revision to the Facebook application, but ended up not making the cut for its August release. The application's developer, Joe Hewitt, quit the project in early November, citing dissatisfaction with Apple's App Store review process.
Update: Facebook Version 3.1.1 is now available, bringing bug fixes for the application's new address book syncing feature.