Currently Being ModeratedNov 29, 2012 11:34 PM (in response to MadSam54)
Add them to your Favorites in the Phone app. then set Do Not Disturb to Allow calls from favorites.
Currently Being ModeratedNov 30, 2012 12:24 AM (in response to rusher2004)
You also have the option to allow persistant callers (Multiple calls in a very short time) to ring thru. Rusher2004 is correct, but the other option would work as well.