Wal Mart (WMT) has been one of a handful of large US corporations taking the lead in retooling their business to be more lean, mean and green.  According to the NY Times, Wal Mart (WMT) has said it’s improved the fuel efficiency of its fleet by 25% since 2005 and has plans to test the use of cooking grease from its delis for truck fuel.  The company credits gains in fuel efficiency to smarter loading techniques, reduced packaging and optimized trucking routes.  Critics say it’s only about the bottom line with Wal Mart and there is much more they could be doing, but it’s a start.  Isn’t it always about the bottom line with corporations?