title: Check iOS version at runtime?
body: <p>This is sort of a follow on from my last question. I am using <code>beginAnimations:context:</code> to setup an animation block to animate some UITextLabels. However I noticed in the docs that is says: <em>"Use of this method is discouraged in iOS 4.0 and later. You should use the block-based animation methods instead."</em></p>
  
  <p>My question is I would love to use animateWithDuration:animations: (available in iOS 4.0 and later) but do not want to exclude folks using iOS 3.0. Is there a way to check to iOS version of a device at runtime so that I can make a decision as to which statement to use?</p>