Bèr Kessels

<?php
function r_join($glue, $field, $value_type = 'view') {
  foreach($field as $field_value) {
    $values[] = $field_value[$value_type];
  }
  print join($glue, $values);
}
?>

Have to see if http://api.drupal.org/api/function/drupal_render/7 makes this fully or partially unnecessary in Drupal 7.

Add ack-grep with a Drupal profile to easily search (just) Drupal files.