This excerpt taken from the AAPL DEF 14A filed Apr 16, 2007.
Grants Of Stock Options. Each newly elected or appointed non-employee director receives an initial grant of an option to purchase 30,000 shares of common stock (an Initial Option). Each non-employee director is also granted an option to purchase 10,000 shares of common stock on the fourth anniversary of the non-employee directors initial election or appointment to the Board and on each subsequent anniversary thereafter (each, an Annual Option). The exercise price of each option is the closing sales price for the common stock on the date of grant. Initial Options vest and become exercisable in equal annual installments on each of the first through third anniversaries of the date of grant. Annual Options are fully vested and immediately exercisable on their date of grant.