A little late reporting on this one. I read about it back in July, but just recently came across some video of the event. From the NY Times:

It was called “77BoaDrum,” and the idea was simple and irresistible: Eye (as he is known) was joined by the other three Boredoms, all three playing drums, along with 74 more drummers from the New York musical underground and beyond, all arranged in a giant spiral. That made 77 drummers, celebrating 7/7/07 at Empire-Fulton Ferry State Park in Brooklyn, at the foot of the Brooklyn Bridge.

Looked pretty awesome to my eyes. Drumming on an oceanic scale.