I'll admit it, I have yet to get Flickr. Online photo sharing to me is called Facebook or Twitter - but for everyone else...
Flickr finally got with the programme and joined the legions of companies today with an official iPhone application. The move will no doubt mean the end of the many third party solutions as Flickr hasn't built something truly hideous like the recent official iPhone Wikipedia app.
What's good? Well, for everyone who isn't me users will be able to shoot, upload and share photos and (if you have a 3GS) videos, geo-tag them (or roughly triangulate with cell towers if you're an original iPhone owner) and add tags. A news stream keeps you up to date with recent photo activities from friends and family while photos can be searched for and viewed by subject, person or place. Photos themselves can be commented upon and marked as favourites.
Early user feedback is extremely positive with the app currently rated at an average of four stars out of five. Crucially (or at least it seems given the abuse the excellent iPhone Spotify app has received for daring to require premium subscriptions), the Flickr app is completely free. You will need iPhone OS 3.0 or later, but it plays equally nicely on iPhones and iPod touches.
Ok, ok, I'll give Flickr another go...
Update: While we're on the subject of official apps, Facebook has just now announced an official app for Android is now in Marketplace. Despite being long overdue, it is horribly limited in its initial form with just the ability to read your wall, news feed, update your status and comment or 'like' posts. Not great, but at least background running does mean a Facebook widget on your home screen can notify you of the latest invites and messages.