Having made some major improvements over the first release of the Facebook App, this new edition is definitely a must have. When it first launched, the app wouldn't even let you view/post on other peoples walls. At it's best, you could consider it an extended contact system for people you didn't want to put directly into your phone book. This all changed of course when the new version of the app premiered.
While you may get lost and not know what button to press to get where at times (like pressing your profile and instead viewing the last profile that you were visiting), you can actually do a lot with this app. You can view your friends profile pictures, their mini-feeds, status updates, wall posts (which includes the ability to leave a wall post in this version), and get their contact info as well.
Unfortunately, you can't search for new friends to add, but you can add new friends if the individual has made a post on the wall of a mutual friend. All you need to do is press their comment and it will give you the option to add them as a friend or send them a message. This app receives straight 4's across the board instead of 5's due to all the little things it lacks that only the full site has been able to deliver.
With Facebook being the largest and most active social networking site currently out there, this app is easily a must have for just about everyone with an iPhone.