Block Nuisance Callers Texters iPhone

I have paid a lot of money for a lgeitimate iPhone, and therefore, dont want to start messing with jailbreaking etc. I have a problem with a nuisance caller, and I have researched on the web to find out how to block unwanted texts and calls from specific numbers. There appears to be two main apps available for doing this - iBlacklist, and mcleaner. Both appear to do exactly what I want, but unfortunately are not available through the App Store, and thus require the jailbreaking of the phone.Does anybody know of another way to achieve this goal? Or, perhaps you know if this functionality will be available in future iPhone firmware updates? perhaps the apps I mention above might even someday be available in the app store? Does anybody have any information?Thanks. PC Windows XP Pro