Override ?Submitted by? text for Drupal nodes?

This is the code you put in your template when overriding submitted by text, there is also a module that helps do some of this things http://drupal.org/project/submitted_by
also take a note that when you want to translate you need to use setting.php technique.

function [your_theme_name]_node_submitted($node) {
  return t('Some text about sumbiting !username on @datetime',
      '!username' => theme('username', $node),
      '@datetime' => format_date($node->created),