[eluser]OverZealous[/eluser] @BrianDHall
That's a great solution.
If I had designed it, I probably would have built-up (meaning, only add "approved" fields), but the nice thing about using unset is you have a much cleaner setup. I think I like your solution better.
Whether that code should be in the model (which, IMO, is easier to maintain) or the controller is up to the MVC die-hards to debate ;-)