title: Convert NSDate from GMT+0 (London) to User's TimeZone
body: <p>I have a NSString (date) retrieved from my MySQL database which is in GMT +000 (London) and its format is like this: 12/05/2011 5:21:29 PM.</p>
  
  <p>I would like to know how I could convert it to the user's time zone so that if the user was in china for example, it would be that date in the chinese time zone. </p>