Love DND -- Can It Be Applied to Individual Contacts? I think do not disturb is a great improvement in iOS 6. I have a super annoying persistent caller but I need to hear their voicemails. Is there any way to have calls from their phone number forward directly to voicemail?
Your service provider should be able to provide that service.  The number would be stopped at the call side, and redirected before it gets to your phone. 

Give them a call.