Is it possible for php(or javascript in the worst case) to create a unique id for a user that is not cookie or ip dependant. I have seen on myminicity.com that on each city the count only goes up once a day(it has a unique id for everyone i think) and even if I delete my cookies and refresh ip it still seems to detect me as visited already and I want to make this system for me. I have seen lots of people saying its not possible and if it really isn’t, whats the best alternative?
EDIT
Now i got the idea that I could use a mix of multiple cookies(with multiple methods of identification), multiple localstorage values(same as the cookies), mysql database ip tracking and flash cookies and if any one of them is found, the user has visited before today.
There are several information a user agent sends to the server. See for example Panopticlick to see how unique your browser is. Another option would be to use Flash cookies that are harder to reject and delete.