To close Poway High School's commencement back in June, two seniors, Zach Harju and Enrico Lopez-Yanez, (as eZ/pZ,) performed a set of parodies, leading and closing with Tenacious D's "Tribute". (In which they called out principal Scott Fisher.) They brought down the house, and it's the coolest thing I've ever seen in a graduation ceremony. It's also quite a statement that Scott let them do it.
It is finally on YouTube.
And for reference, there's a FLV/SWF player for OS X.