I've become fascinated with these quirky little videos. The idea is that you take video clips from kids shows, and edit them to create all sorts of amusing and unexpected possibilities.
You search for "Youtube Poop", or "Youtube Poop Mario" or whatever you're looking for, and click on the high-rated ones. Or you can look in the "Related Videos" box, which displays similar videos through a magical process I don't fully understand.
My favorite poops are the ones that splice and edit dialogue, and have a kind of story. There are lots of poops that just have Mario dancing around to techno music...any idiot could make those.