Cover albums are notoriously difficult to pull off.  Releasing a collection of tracks by bands better than your own (*cough* Puddle of Mudd) that sound exactly like the originals is one of the laziest ways to finish up a record label contract and insure that the rest of the world thinks your a bit of a plank.  On the other hand take an original song and make it your own (Marilyn Manson being an expert at this) and it can kick start a career.  However you get the impression that Les Claypool’s Duo De Twang don’t really care about career progression or probably even what other people think about them, this is an album that feels like it was made purely for fun.