Keep Circulating the Tapes: The release of their song "5 Needs" from Biodome only got a release through pre-orders of Rize of the Fenix on iTunes, so unless you pre-ordered it, you're shit out of luck finding a good quality version of the song.
The Danza: Paul, the open mic host, played by Paul F. Tompkins. And of course, Jack Black and Kyle Gass are also their real names.
Screwed by the Network: Part of the reason the show ended so quickly is because HBO, when offering them more episodes, wanted to remove Gass and Black as executive producers. Balking at this, they instead decided to record an album, and then produce a movie (which became Tenacious D in The Pick of Destiny).