This excerpt taken from the AMZN 8-K filed Sep 18, 2007.
4.9 Vice President
In the event of the death of the President or his or her inability to act, the Vice President (or if there is more than one Vice President, the Vice President who was designated by the Board as the successor to the President, or if no Vice President is so designated, the Vice President first elected to such office) shall perform the duties of the President, except as may be limited by resolution of the Board, with all the powers of and subject to all the restrictions upon the President. Any Vice President may sign with the Secretary or any Assistant Secretary certificates for shares of the corporation. Vice Presidents shall have, to the extent authorized by the President or the Board, the same powers as the President to sign deeds, mortgages, bonds, contracts or other instruments. Vice Presidents shall perform such other duties as from time to time may be assigned to them by the President or the Board.