Giving Incentives to Volunteers Everywhere Act of 2008 or the GIVE Act of 2008 - Amends the Internal Revenue Code to: (1) increase the standard mileage rate for use of a passenger automobile for charitable purposes to 70% of the current rate for business usage; and (2) exclude from the gross income of charitable volunteers reimbursements paid to them for the use of a passenger automobile for the benefit of a charitable organization.