The act of walking "around the block" without retracing your footsteps and always finishing where you started. You may only block where there is a path or a street so most people practice it in urban areas. Also, no blocker may ever wear yellow socks!
A technique used in social networking when one doesn't want to communicate with a particular person any more. Usually involves going to the residence or workplace of the offender and beating their face in with a cinder block.