Some states will refund sales taxes on certain items and up to a certain amount. You can not just go in with an out of state ID and claim you don't have to pay taxes, they will laugh at you.
In New Orleans, there is a place at the airport where you can bring your receipts, your out-of-state ID, and your plane ticket and they will refund the state taxes you paid on things you are leaving the state with. (city taxes are not refunded) You can also pick up a form and mail in a claim when you return.
Some other states have a similar program.
I use the one in Canada all the time - when I return from a business trip, I mail in copies of my hotel bill, clothing items I bought, etc., and they refund the GST I paid on it. The taxes on 7-day hotel stays can really add up and it's nice to get some of it back. Of course, my company paid for the room, *I* claimed the refund.
