My favorite festival Newport Jazz Festival. or Newport Folk Festival.
I went to the "IT" festival and it was a dream world. Barefooted drunk and high people everywhere playing music, relaxing, riding scooters, mopeds, skateboards, selling cheap food and jello shots, and sleeping in tents and on grass fields.
This is becoming very popular! Treasure Island is clean, serene and has amazing views of SF, Sausalito & East Bay. It would be awesome to spend your birthday there -tell vendors b/c you might get some comps too. You never know. Happy Birthday man.
All the details are here: treasureislandfestival.com