Other
Pandora and the Music Genome Project
As soon as Julia told me about Pandora, I began listening to it almost continuously. You tell it what you like, and it plays similar music. I've learned about many artists I hadn't known through it.
Learn to solve a Rubik's cube quickly
10 minute tutorial
One Laptop per Child
Sounds like just an ambitious project that could never possibly happen, but it seems like it's for real, and it should be quite a revolution. There's a talk by one of the people in the program here: http://mitworld.mit.edu/video/435/
