A pair of submissions to NBAA’s Air Mail Internet forum underscore the importance of preflight awareness. A Challenger crew taxiing for takeoff from an unattended airport received a radio call (from an unspecified hero) alerting them to a potentially dangerous situation. Unable to remove the small-airplane chock from behind one of the mainwheels, the crew had moved the front chock out of the way and started up. Unknown to them, the rear chock stuck to the tire and, as the aircraft began to roll, wedged itself onto the trailing link of the main gear. That left the front chock dangling by the connecting rope. Alerted to the danger, the crew shut down and removed the chocks–thankful they had not got airborne and tried to retract the gear. A second Air Mail posting from another pilot recalled a similar close shave involving his Falcon 900 nosewheel at Orlando Executive Airport (ORL). An alert Showalter Flying Service lineman noticed a missing set of chocks and called the tower, which alerted the crew to the fouled nosegear before takeoff.