How to add a custom button to a UINavigationBar (a la Foursquare)

Programming for ios: How to add a custom button to a UINavigationBar (a la Foursquare) on newest questions tagged ios – Stack Overflow

Im going through the different options of creating a custom UINavigationBar and since my app is iOS 5+, i am using this code:

// Set the background image all UINavigationBars
[[UINavigationBar appearance]  setBackgroundImage:NavigationPortraitBackground
                                    forBarMetrics:UIBarMetricsDefault];

Now i want a custom image button on the very right side and am a bit lost. Should I go another way, subclass UINavigationBar and add a button to it or would there be an easier way?

source: http://stackoverflow.com/questions/11287422/how-to-add-a-custom-button-to-a-uinavigationbar-a-la-foursquare
Programming for ios: programming-for-ios