title: How to remove old versions of iPhone SDK when installing the new one?
body: <p>I have downloaded iPhone SDK 4.0.2, I wanted to install it, but it looks that I don't have enough space. This made me think that maybe I could unistall the previous versions of iPhone SDK and install only the newest one.</p>
  
  <p>Does anyone know how to do this?
  Should I keep the old versions? Is there any situation they could be useful?</p>
  
  <p>Thanks for sharing your thoughts!</p>