I needed a way to flip a multidimensional array and came up with this function to accomplish the task.  I hope it helps someone else.

<?php
function multi_array_flip($arrayIn, $DesiredKey, $DesiredKey2=false, $OrigKeyName=false) { 
$ArrayOut=array();
foreach ($arrayIn as $Key=>$Value) 
    {
        // If there is an original key that need to be preserved as data in the new array then do that if requested ($OrigKeyName=true)
        if ($OrigKeyName) $Value[$OrigKeyName]=$Key;
        // Require a string value in the data part of the array that is keyed to $DesiredKey
        if (!is_string($Value[$DesiredKey])) return false;

        // If $DesiredKey2 was specified then assume a multidimensional array is desired and build it
        if (is_string($DesiredKey2)) 
        {
            // Require a string value in the data part of the array that is keyed to $DesiredKey2
            if (!is_string($Value[$DesiredKey2])) return false;

            // Build NEW multidimensional array
            $ArrayOut[$Value[$DesiredKey]][$Value[$DesiredKey2]]=$Value;
        }

            // Build NEW single dimention array
        else $ArrayOut[$Value[$DesiredKey]][]=$Value;
    }
return $ArrayOut;
}//end multi_array_flip
?>