The first weekend in August every year, many states have a sales tax holiday related to back-to-school shopping, including Alabama, Arkansas, Florida, Georgia, Iowa (clothing only), Louisiana, Missouri, New Mexico, Oklahoma (clothing), South Carolina, Tennessee, and Virginia. Texas observes this next weekend (Aug 8-10, 2014). Through tomorrow, anyone can save a little extra on allowed items for your state. Clink the link on your state to find the details. Check this Sales Tax Holidays summary for more sales tax holidays throughout the year.
Note: In Missouri, many cities do not participate in the Sales Tax Holiday, including Columbia, so you only get a discount of the state portion of the sales tax. For a list of Missouri cities, click here.