title: Get iPhone ID with web app?
body: <p>I'm making a web app for iPhone.  I have some settings that the user can set, but I'm not sure how to save the settings for that iPhone.  I don't want the user to have to sign up for an account.  Is there a way to get a unique identifier for the iPhone (serial number, etc).  So basically, what is a unique identifier, and how could I retrieve it with a HTML5 web app?</p>
  
  <p>Thanks!</p>