Are you and your team staying at the Westfields Marriott Washington Dulles for the DC Open? If you are, then you get a 10% discount on all meals (alcohol not included) at the Texas Roadhouse next door. Just show your room key to your server or the manager and you get the 10% discount off your total bill.
UPDATE: You do not need to be staying at the Marriott to get the 10% discount anymore. The 10% discount has been extended to everyone that is participating in the DC Challenge. Just show them your PEVS card, in your team packet given at registration, and you get the discount.