There have been a lot of unofficial Flickr apps on the iPhone, but none have done as good a job as the newly released official app does.
After only a little bit of time using it, I can tell that I’m going to like it. The main screen is a fairly mesmerizing slideshow of photos from your contacts on Flickr. There is an upload button that is easily accessible right on the main page, and the upload process is nice and easy. You can obviously name your picture and give it a description, but you can also easily manage what set to put it in, and what tags to give it. And the privacy settings are very clearly displayed on the upload page.
I agree — it’s a very solid app. I’ll still be using PixelPipe for most of my photo uploads so that they’ll go to more than just Flickr, but this will be a great app to have on the phone.