PS: unfortunately the 7:30 AM is full, but I highly recommend the instructor Douglass - I've taken his class at Yogaworks and it's wonderful! http://www.yogaworks.com
Duffy Square (Broadway and 7th Ave near 46th street) becomes ground zero for hundreds (thousands?) of yogis saluting the sun on the longest day of the year. Bring your mat and join in. Local teachers give talks and classes during the day. Last year, the first 1500 yogis snagged some swag.
When: June 21 starting at dawn and going to dusk
Where: Times Square between 46th and 47th Street