YouCube is a great site I learned about from the excellent blog, Zarco English. It is a place where users can publish YouTube videos onto a 3-Dimensional cube.
I can see this being used in a class (w/ appropriate guidelines) where students pick videos of a "central" theme and then link those videos together via the cube. For example, lets say students were doing a science project on plants, they can select videos of certain topics that have to do w/ plants and post them to the cube (ex, photosynthesis, chlorophyll, etc).
Below is my YouCube example of Common Craft videos...
Give YC a try by clicking here.