use xmlrpc to authenticate and create a node via services module 3.x and drupal 7
Note: this is valid after SERVICES 3.5 (lower version are deprecated, anyway)

// USER LOGIN
$authenticate = xmlrpc($settings['server'], Array('user.login' =&gt; array($settings['user'] , $settings['password']),));

// CREATE HEADERS
$options['headers']['Cookie'] = $authenticate['session_name'] . '=' . $authenticate['sessid'];

// GET TOKEN
$token = xmlrpc(url($this-&gt;endpoint, array('absolute' =&gt; TRUE)), array('user.token' =&gt; array()), $this-&gt;headers);

//INSERT TOKEN INTO HEADERS
$options['headers']['X-CSRF-Token'] = $token['token'];


At this point you should be authenticated and could create nodes at will.