I wish I could participate in this deal! Through August 8 at Six Flags America in the Baltimore/Washington, DC area, purchase a 1-day adult admission ticket for $19.99 using coupon code "FEDERAL". (You must first select the correct park and then enter the code in the promo code box in the top right-hand corner of the page.) That's $10 off the current discounted price!
I'd love to hear from you!