In Pictures: iOS 7 tips and tricks you need to lea...
Block specific callers
You can block numbers from being able to call, initiate FaceTime conversations, and send messages to your phone. This is a great way to keep stalkers or telemarketers from being able to contact you ad nauseum.
To block a caller, go to a contact's entry, scroll to the bottom and select "Block this Caller."
In Pictures: iOS 7 tips and tricks you need to learn