When we were at Macchu Pichu June of 2011, the permit for Huayna
has to be obtained in person on the day. So people has to get on the first bus before hike to the park entrace before 6:00am. However, I heard from 迪子's blog that people can book the permit for Huayna Pichu now. However, it has to be attached to a MP ticket. So for those who hike to MP vis Inca Trail, this mean one extra ticket to buy.