This excerpt taken from the AAPL DEF 14A filed Apr 16, 2007.
Elements of post-termination compensation and benefits. All Company employees, including the executive officers, are employed at will and do not have employment agreements.
Severance. A standard Severance Plan that provides for two months of pay regardless of length of service or level applies to all Company employees.
Change-in-Control Provisions. Except with respect to the provisions of certain equity awards, as described in Change of Control ArrangementsStock Options and Restricted Stock Units, executive officers do not have change of control agreements. Moreover, none of the executive officers have any agreements with the Company to be grossed up with respect to any golden parachute excise taxes.