title: Grant CCK Field edit rights to a user referenced from User Reference; Drupal
body: <p>In Drupal I am trying to create a content node where the original author can upload an image and then 'challenge' another user to upload an image into that node as well.
  I can already grant the 2nd user access rights through CCK > User Reference > Node Access User Reference but I don't want that new user to be able to edit the whole node, only 1 imageFile field.
  Is there any way to do this Grant Per User Field Access User Reference?</p>