As a candidate, Barack Obama promoted hybrid cars. As president, he'll be handed the keys to one. Sort of. Shortly after taking the oath of office, Obama will climb into the Mother of All Hybrids -- part car, part truck and, from the looks of it, part tank. In keeping with recent tradition, the Secret Service will place a brand-new presidential limousine into service January 20 to drive the new president on the 2-mile jaunt down Pennsylvania Avenue during the inaugural parade. Already, spy photos of the limo -- with patches of gray primer -- have leaked out. And already,...