Change content "Author" to the last "Editor"
If you have a custom module to use, or aren't afraid to make one, then a hook_node_presave is the first method I would try.

function yourmodule_node_presave($node) {
  // php5 passes objects by reference
  // so this should not need a &amp; or return
  global $user;
  $node-&gt;uid = $user-&gt;uid;
}


If you do not want to go with code, then try the Rules module.  Rules has a trigger for node about to be saved.  Set the condition that the current user is not anonymous (because rules likes you to confirm in a condition any data you want to use in the actions) and then set the author field in the action to the current user.  All done in the ui, no new code needed.