he San Francisco 49ers signed cornerback Nate Clements and safety Michael Lewis, making two bold moves in the opening hours of free agency. Clements, the star cornerback from the Buffalo Bills, agreed to an eight-year, $80 million contract. The six-year veteran was considered one of the top prizes in free agency, and the 49ers rewarded him accordingly with what's believed to be one of the richest contracts for a defensive back in NFL history. Terms of the deal were confirmed by a person familiar with the negotiations. The person spoke to The Associated Press on the condition of anonymity because contract terms aren't usually released by NFL teams.