lammert - 3:58 pm on Jul 20, 2010 (gmt 0)
Hi AngelX, first of all Welcome to WebmasterWorld!
Many solutions which are available for country determination based on IP address are also available on state level. You should however know that the smaller the discrimination level you require, the larger the error will be. Especially with large ISPs like AOL which use a number of proxy servers to tunnel all client traffic through, it will be difficult to know exactly from which state a visitor is coming from.
If you have some knowledge in programming in for example PHP, a solution which uses a local IP database on your web server would be the simplest and fastest solution.