title: Any way to identify a mobile phone web user other than using a cookie?
body: <p>I have a web page which will use a rating system entered by web user. There's no login functionality. Web page is mainly accessed by mobile phone users. On a desktop computer I can use the browser's ip address and cookie to determine if user visited the web page earlier. I will use the ip address also for users who erase their cookie. If the ip address is in database, the user is not new. (ignoring shared ip addresses like AOL)</p>
  
  <p>For a web user on a mobile phone or device, is a cookie the only way to identify a prior user?
  Is it true mobile phones do not have ip addresses sent by the phone's browser?</p>