This fall, Stanford opened three of its courses to free online enrollment: Machine Learning, Databases, and Artificial Intelligence. Over 100,000 people signed up.
This winter they've expanded to 16 courses. I didn't see a directory anywhere so here is the complete listing:
Starting late January
Starting in February
Software as a Service (from Berkeley)
Starting in March
If you're not sure you want to dive in, sign-up anyway... it's free option value and sign-ups close once the course starts.
I'll be taking (or at least starting) Human Computer Interaction, Design and Analysis of Algorithms, and Model Theory in January. I took Machine Learning in the fall and Ng was a great teacher.
If you want to try Stanford courses independent at your own pace, check out Stanford Engineering Everywhere. I first learned to code through 106A and highly recommend it. I'll be attempting the iPhone course this winter.