A Nevada City woman transformed her life by trading in her SUV for a motorcycle, replacing all the lightbulbs in her house with energy-efficient bulbs, taking in a roommate, cutting down on meat consumption and saying goodbye to her cell phone. "These are really easy, manageable changes that make a difference. That's all we ask of people," Reinette Senum said as she talked from the steps of Nevada City's United Methodist Church at the top of Broad Street. Senum is the seed of APPLE, the Alliance for a Post-Petroleum Local Economy, a grassroots group concerned about high-priced and limited supplies …