MCleaner is 3rd party software for the iPhone which can manage your SMS and calls, and block those you don’t want automatically. It can filter incoming calls and SMS messages according to pre-configured keyword and phone numbers (could be partial match), and you can set a profile to get MCleaner working mode quickly. Also scheduler mode is supported and you can browse blocked calls or messages details anytime.

Note: This app is shareware and is distributed via Installer.app. There is a 15 day free trial after which it will cost you $19.00. To install it you must add this source to Installer.app: www.mcleaner.com/iphone/install

Use iPhone mods and hacks at your own risk! Installing 3rd Party iPhone apps requires you to jailbreak the iPhone before installing the native software and apps. You can use Installer.app for Mac OSX and iBrickr for Windows PC to do this. Browse the full list of all iPhone and iPod touch native 3rd party apps filed under the software category.

Details here