ST. HELENA, Calif. -- Unable to drive down high oil prices, President Bush is spending Earth Day promoting futuristic hydrogen fuel technology as a way to wean Americans from gas-guzzling vehicles. After a bike ride near his Napa Valley resort Saturday morning, Bush planned to visit the California Fuel Cell Partnership in West Sacramento for a tour and speech on his energy plan. The plan does not include any measures that would reduce gas prices in the short term, the White House acknowledges. But with Republicans worried that the increasing cost to drive could hurt them in the voting booth...