Result:

Hey, I live in London, England and on Monday I fly to Nuremberg via Zurich,Switzerland (sadly enough).

• London, England, GB, Town (51.5063,-0.12714)
• Nuremberg, Bavaria, DE, Town (49.4543,11.0739)
• Zurich, Kanton Zürich, CH, Town (47.3771,8.53955)

Source:

  $content = 'Hey, I live in London, England and on Monday '.
             'I fly to Nuremberg via Zurich,Switzerland (sadly enough).';
  $key = 'GET_YOUR_OWN_KEY';
  $ch = curl_init(); 
  define('POSTURL',  'http://wherein.yahooapis.com/v1/document');
  define('POSTVARS', 'appid='.$key.'&documentContent='.
                      urlencode($content).
                     '&documentType=text/plain&outputType=xml');
  $ch = curl_init(POSTURL);
  curl_setopt($ch, CURLOPT_POST, 1);
  curl_setopt($ch, CURLOPT_POSTFIELDS, POSTVARS);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);  
  $x = curl_exec($ch);
  $places = simplexml_load_string($x, 'SimpleXMLElement',
                                  LIBXML_NOCDATA);    
  echo "<p>$content</p>";
  echo "<ul>";
  foreach($places->document->placeDetails as $p){
    $now = $p->place;
    echo "<li>{$now->name}, {$now->type} ";
    echo "({$now->centroid->latitude},{$now->centroid->longitude})</li>";
  };
  echo "</ul>";