This excerpt taken from the HPQ DEF 14A filed Jan 27, 2010.
$100,000 Limitation. Notwithstanding the designation Incentive Stock Option in an Option Agreement, if and to the extent that the aggregate Fair Market Value of the Shares with respect to which Incentive Stock Options are exercisable for the first time by the Awardee during any calendar year (under all plans of the Company and any of its Subsidiaries) exceeds U.S. $100,000, such Options shall be treated as Nonstatutory Stock Options. For purposes of this Section 9(b), Incentive Stock Options shall be taken into account in the order in which they were granted. The Fair Market Value of the Shares shall be determined as of the Grant Date.