title: IPod Touch upgradable?
body: <p>I am interested in picking up an IPod in order to be able to test my apps on both the IPhone and IPod.  I don't really care about the IPod for any other purpose, so I'd be willing to buy a used one.</p>
  
  <p>But the question arises, does an old IPod lack any features or software upgradability that would limit the type of apps I could test on it?  I know nothing about IPods and whether they have evolved their operating system with newer models.</p>
  
  <p>Thanks for any information on this.</p>