Got a call about 1/2 hour ago on my cell phone. After reading these posts, no sense in calling back to be removed from their call list (lets them know they contacted a good number)...I just blocked them on Call Control! :)
If you have an android based phone, you can also make it so that that contact will automatically be forwarded to voicemail or not ring at all. Just view the contact, tap the menu button and depending on the skin your phone uses, it'll either have a settings option or a direct to voice mail option. Very helpful so that you're not even bothered with the phone call in the first place.