I'm having this really mind breaking problem.
I created a Localizable.strings file in XCode and then 2 languages in it.
I filled up these files with the language translations, did a build/clean and then a fresh build, but there is no way the Localization strings show up in my project. If I try something like:
self.title = NSLocalizedString(@"HEAD", nil);
I found the answer myself.
Besides cleaning and building the project again and all that I described above. You must also delete the app in the iPhone simulator and then build it again! After that it works perfectly.
Talk about making it simple Apple...