owncloselady-lm:scratch rbush$ perl hmap_ex1.pl 
new = $VAR1 = {
          '1' => {
                   'nick' => 'rbush',
                   'bday' => '3/12/1965',
                   'phone' => '5551212'
                 },
          '5' => {
                   'nick' => 'fred',
                   'bday' => '5/01/1972',
                   'phone' => '1112300'
                 }
        };

new2 = $VAR1 = {
          'rbush' => 'bday',
          '1' => 'nick',
          '3/12/1965' => 'phone',
          'nick' => 'fred',
          'phone' => '1112300',
          'bday' => '5/01/1972',
          '5551212' => '5'
        };