We released our first paid iPhone app at ZenRockers. The app is part of our danish dog owner community.
It started making a bit of money before we even had a chance to announce it. Which makes it a lot easier to accept that Apple takes 30% - they've created an impressive software marketplace.
The only downside is that we found a critical bug on iOS 5.1 that prevented the app from even getting past the start-up screen. I usually have no problem with the App Store review time and we haven't done much marketing so only a few 5.1 users have the app. But it is a long week when you have an app that crashes on 20-30% of iPhones.