Travelers to the US must have machine readable passport as of 6/26/2005!
The Departments of Homeland Security and State advise that, commencing 6/26/05, all VWP travelers without visas must possess machine readable passports to be admissible to the United States. Substantial fines will be imposed on carriers found to be in violation.
Posted on AILA InfoNet at Doc. No. 05051269 (May 12, 2005) .