The Giants officially announced the re-signing of David Carr yesterday, to serve as Eli Manning's back-up for a fifth season. The team feels comfortable with Carr, who was the former No. 1 overall pick of the expansion Texans. Another factor? They like his ability to run the scout team and accurately mimic the opponent's quarterback each week -- even the option-style quarterbacks, like Washington's Robert Griffin III, that gave defenses headaches last year.