Aug 3-5 is tax free weekend for North Carolina, South Carolina, Alabama, Georgia, Missouri, New Mexico and Tennessee. You could save bunch of money on buying college supplies.
Sales tax varies between states. Following link gives list of tax holidays. Not all the items are eligible for tax free. List of eligible items will be list in state government site. I went to Best Buy to take a look at few laptops and had to wait in queue for 15 minutes to take advantage of this tax free weekend.
For students it will be good saving, when buying laptops. It will save you around $50 to $150. You could use that upgrade your RAM.
Lenovo( Thinkpad) had some good promotions for this tax free holidays with list of states listed, that has tax free holidays.
Tax free weekends depends on when schools are scheduled to open. So, keep an eye out for your state.