At one point in time, Shaun Stenshol was an environmental activist who spent a lot of time getting arrested. Now, he runs a bio-fuels car rental service in Hawaii. He claims that the idea works on multiple levels. Not only do travelers get to drive an eco-friendly car while they visit this island state, he says, they also get to “test drive” one in case they’d like to buy one in the future. His idea has caught the attention of a lot of folks, including the magazine Business Week, who wrote this feature article about him last week.