Actually my title is quite misleading because these clips are an example of how too much time on one's hands can be a cool thing. There is someone out there in internets-land who did a bunch of Metallica songs on solo piano. I must say, color me impressed. I'm sure if you take the time you too will be impressed with this gal's (!) work.
"Master Of Puppets"
"The Call Of Ktulu" (probably my favorite of all the ones she did)
"The Day That Never Comes"
"Harvester Of Sorrow"