How to tell is this is a user's first visit?

[eluser]jayrulez[/eluser]
[quote author="Yorick Peterse" date="1246831816"]Use a database, that's the only possible way of doing it. Simply store the IP address. When loading the page check to see if the user's ip is already in the database and you're done.[/quote]
there will be discrepancy in the case of sharedd ips

[quote author="FlashChilli" date="1246831607"]Hi everyone,

I'm new to CodeIgniter and I'm amazed how much faster I can develop PHP with it, I just have two questions.

1. Is there a way to tell if this page load is a user's very first visit to this website? (I'm using the sessions class and Redux Auth). I know that you would need to check if a cookie exists or not but, if it didn't then wouldn't it be created by the session class before your code is executed?

2. Oh dear, I've forgotten my second question. I'm sure I'll remember it soon... I hope : )[/quote]

You said you're using Redux Auth, correct? Is your question simply "how to tell if it's the user's first visit?" or do you want to check when the first time hte user logs in is?