Activision and Infinity Ward are inviting players to play Call of Duty 4: Modern Warfare on Wednesday, October 17 at select GameStop locations. Those who get there at 2100 hrs (9:00pm, local standard time) will get the chance to try out the single player version before the public release on November 6th. For more information, including a list of participating GameStop locations, visit this page. The PC demo can be found here.