The U.S. Postal Service still remains vulnerable to fuel price  fluctuations despite cost containment efforts and increased revenues  from the January 2006 rate increase. The U.S. Government Accountability Office report called U.S. Postal  Service: Vulnerability to Fluctuating Fuel Prices Requires Improved  Tracking and Monitoring of Consumption Information, published last  week, was done at the request of Congress and concluded the agency  must improve the tracking and monitoring of its fuel consumption. The [USPS] absorbed fuel cost increases through cost containment  efforts and increased revenues from the January 2006 rate increase,  allowing it to achieve net income for the year, the GAO said.  Nevertheless, the [USPS] remains vulnerable to fuel price  fluctuations, due in part to its purchasing process, which involves  buying fuel as needed, often at retail locations.