This excerpt taken from the HPQ 10-Q filed Jun 8, 2007.
IX. LOANS FOR EXERCISE OF OPTIONS
Any option agreement under this Plan entered into with an employee may, but need not, provide that the Company shall lend to the employee who holds the option the funds for any exercise of his option. Any such loans made to individuals subject to Section 16 of the Exchange Act shall be at a rate of interest adequate to avoid imputation of income under Sections 483 and 7872 of the Code and shall be for a term not to exceed 15 months from the date of exercise of the related option. Any loan by the Company to fund the exercise of an option shall be subject to such other terms and conditions as shall be set forth in the option agreement, which terms and conditions shall be determined by the Committee at the time of the grant of the option. Loans may or may not be secured by stock issued pursuant to such option exercises, at the Committees discretion.