title: What are possible 3rd Party Payment Systems to integrate in iPhone Apps?
body: <p>Apple states in its <a href="http://developer.apple.com/appstore/resources/approval/guidelines.html" rel="nofollow">App Store Review Guidelines</a> "Apps using IAP to purchase physical goods or goods and services used outside of the application will be rejected". So is it then legal to implement other payment services than Apple's In-App-Purchase to buy physical goods? I could imagine services like PayPal, Amazon or Google Checkout but don't have any experience with those and if they are usable within iPhone Apps.</p>