The pilot reported he was taxiing his airplane fairly fast with the tailwheel raised. He said he lost control of the airplane and ground looped. Postaccident inspection disclosed a piece of World War Two-vintage communication wire wrapped around the left main landing gear axle and brake assembly. The pilot said he was unsure if the wire was picked up during the taxi just prior to takeoff, or at an earlier time. He indicated in his written statement that he now performs a closer inspection of his airplane prior to each flight.