title: What is the best way to make a UIButton checkbox?
body: <p>I am trying to make a standard check box for my iPhone app from a <code>UIButton</code> with a title and image.  The button image changes between an "unchecked" image and a "checked" image.</p>
  
  <p>At first I tried subclassing <code>UIButton</code> but <code>UIButton</code> has no <code>-init***</code> method to use in my <code>-init</code> method.</p>
  
  <p>What is the best way to do this?</p>
  
  <p>Thanks in advance.</p>