On Wednesday the lights on the Christmas tree at the Rockefeller Center were switched on with all the razzamatazz that only New York can do.  A few blocks away at the London Metal Exchange introductory course other lights were being turned on as participants delved into the inner workings of the exchange, and practised using futures and options.  One by one the puzzled faces relaxed and smiled once the concepts were understood and each became more confident.  Instead of an ice rink, golden angels and the Radio City Rockettes, there were aluminium and zinc processors, physical traders, a financial player and even an animal feed supplements manufacturer.