Three Houston landmarks are visible in this photo taken by an Expedition 10 crewmember. Minutemaid Park is the bright rectangle on the left side. The dome on the right side is the Toyota Center. At top center in the photo is the George R. Brown Convention Center.
While it's questionable whether you can see the Great Wall with the unaided eye from space the myth that it is the only man-made object visible has definitely been busted.