I think everybody here likes at least on of Weird Al's songs (especially his recent White and Nerdy), so I thought I'd link my filk archive.
This is stuff my friends and I have written over the years. Starting with my Star Wars parodies I wrote for the Cult of Piett.
http://www.geocities.com/tee-moss/Jukebox
Just to get it out of the way. Filk is a geeky sort of song that is usually a parody of a mundane song but not always. Some filk has original lyrics and music. Filk music got its name from a convention back in the 70s where there was a typo on the program for a Folk Music show. There's actually good debate in fandom over what convention or newsletter was first respnsiblie for the term.
Let's not worry about that though. Do any of you know some good geeky filks?