Don't forget that tax free also applies to online Apple Store orders which is $60+ per $1000 spent.
These states offer tax-free shopping days during the month of August:
Alabama Aug 3-5
Georgia Aug 2-5
Missouri Aug 3-5
North Carolina Aug 3-5
South Carolina Aug 3-5
Tennessee Aug 3-5
I've only listed states that computer purchases apply.
My home state of South Carolina is the most liberal with the things it applies to with very few restrictions. Most states have $ amount limitations.