I searched and could not find this. It would seem by setting a custom ringer for a user in your contact list, then selecting the "Advanced" option under "Profiles" you could have a user ring through even if your phone is on quiet. It doesn't work that way though, apparently.
I would like to be able to put my phone on silent while sleeping, then only have my phone ring when certain people call. This would eliminate the most of the riff-raff, while ensuring only the calls I want to take wake me up.
Is this possible?