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

Technology Entrepreneurship

Model Thinking

Human Computer Interaction

Natural Language Processing

Probabilistic Graphical Models

Cryptography

Design and Analysis of Algorithms I

Machine Learning

Anatomy

Making Green Buildings

Starting in February

The Lean Launchpad

Computer Science 101

Software as a Service (from Berkeley)

Game Theory

Computer Security

Starting in March

Information Theory

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.