title: Generate a UNIQUE ID like Youtube's Playlist - PHP
body: <p>I have read <a href="http://kevin.vanzonneveld.net/techblog/article/create_short_ids_with_php_like_youtube_or_tinyurl/" rel="nofollow">this tutorial</a> many times, finally, i finished to create my own unique id like Youtube.</p>
  
  <p>But i can't find out how to create this kind of unique ID:</p>
  
  <p><a href="http://www.youtube.com/playlist?list=PL124C2FA58C814231" rel="nofollow">http://www.youtube.com/playlist?list=PL124C2FA58C814231</a></p>
  
  <p>Some examples:<br>
  E5DBC5AD85E952BF<br>
  F26D47E15E785137<br>
  4DE9165CE24633D0<br>
  26B44580D7ECDCD3<br>
  --- with prefixes PL --<br>
  PL3F16C0AE0309BB56<br>
  PL124C2FA58C814231  </p>
  
  <p>How can i create that kind of unique id using PHP? My database used auto incremental PRIMARY KEY.</p>
  
  <p>Thanks.</p>