Facebook has a nice strategy for their iPhone app. It mainly displays web views, so they can have the flexibility of a web site without having to go through an Apple review every time they update their features. And as a side-effect other mobile browsers benefit from the same work.

Edit: And now after playing with the new iPhone version, they replaced even more of the app with web views. At this point, it's essentially the same as m.facebook.com but with custom handlers for the Status / Photo / Check In buttons that allow for location awareness and photo uploading.

Thanks for tipping me off to that - it seems substantially less buggy than the app. Faster too, oddly enough.