title: UIPickerView with many different lists
body: <p>I am writing an application that uses a UIPickerView and populates its list items depending on previous selections by the user.  I was reading this <a href="http://www.leesilver.net/1/post/2011/07/uipickerview-how-to-populate.html" rel="nofollow">article</a> and stumbled across his mention of "tags" and could not figure out how this was used.  Can someone please give me a recommendation on the best way to accomplish this, and if this "tag" feature is it, just explain how it is used?</p>
  
  <p>Thank you!</p>