I realize the ios sandbox prevents you from viewing the contents of an SMS msg, but is there some kind of workaround? What about if the msgs are sent to a skype or google voice number, could an iphone application access the numbers then? Thanks.
In a sandboxed environment, No, you cannot access information in other applications or databases outside of your applications sandbox. There is simply no way to do it without being jailbroken. Apple would not allow such an app in the App Store either.
When you sign and package your app through Xcode (for submission to the iTunes App Store) it is packaged for distribution through a very specific process. Apps distributed this way are sandboxed. There is no way around this process for app packaged for the App Store.