title: How to perform some action during several seconds?
body: <p>I would like to know how can I display a view for about 3-4 seconds in iOS 5 ?
  I searched on the web, I found NSTimer but I don't know how to use it in my purpose...</p>
  
  <p>I think a have to create my view, display it, then start the timer or something like that during 3-4 seconds, then hide my view when my timer has finished.
  But how to use this famous timer ?</p>
  
  <p>Thanks a lot in advance !</p>