Something I stumbled on a few days ago. Right now there are three courses you can sign up for:
Introduction to Artificial Intelligence
Introduction to Databases
Machine Learning
The courses will start on October 10th and end on December 18th. They're free and open to anyone interested.
Personally I've signed up because they coincide with subjects that are going to be part of my actual Computer Science studies over next two semesters. Having some advance knowledge never hurts. :-)