While pundits and politicians debate the feasibility of ethanol, switchgrass, and other alt-energy sources, Los Angeles-based Lovecraft Biofuels is busy making cars run on vegetable oil. The autohouse will convert any diesel engine in an afternoon, for about $700. They also have a handsome fleet of converted Reagan-era Mercedes Benzes for sale, going for about $6,000 each. Forget any preconceptions of flubber-like complexity: Lovecraft's engine conversions are driven by founder Brian Friedman's imperative to "simplify, simplify, simplify." And business is brisk: the company performs about four conversions a day.

As for fuel, a nationwide network of biofuel stations already exists: grocery stores. New vegetable oil is available in bulk (around $2.60 a gallon at Costco; cheaper if you buy expired stuff). Those willing to forge friendships with deep-frying restaurateurs can fuel up for free, collecting used cooking oil and filtering it at home.

Friedman's ambitions include developing a conversion kit for every kind of diesel engine, and he talks about a future fueled by vegetables—with vegetable-powered farm equipment harvesting crops, vegetable-powered machines turning those crops into oil, and vegetable-powered big rigs taking that oil to consumers. An utopian vision, yes, but with gas prices creeping ever skyward, it is also beginning to seem elegantly sensible