From Bert Brantley, gov's office spokesman:
The price gouging statute goes into effect upon signing of the executive order, so anything from earlier today would not be subject to sanctions under this statute.
Remember that just because prices go up doesnt mean there is gouging going on. As long as the retailer can show the wholesale price correlates to the retail price, theres no problem.
UPDATE: This is the telephone number to report gas price gouging, if you kept the receipt: 800-869-1123, courtesy The AJC.
If you didn't really need gas, but bought it anyway, save the phone call and punch yourself in the face.