Eli Whiteside must know how Joe Biden feels, because vicepresident of the United States and backup catcher on a playoff teamhave a lot in common. Both are invisible and get little notice or praise, but theymust be prepared to assume a critical job at any moment. As the Giants bulled through October,Whiteside was one Buster Posey misstep from having to catch one ofbaseball's best pitching staffs in the playoffs and WorldSeries.