Free geeky courses from Coursera.org (list of interesting ones inside)
Coursera.org offers free online classes from some pretty swanky schools. The courses consist of video lectures, quizzes, etc. They are somewhat self-paced in that they have start and end dates and due dates for things, but you have flexbility within that format. You don't have to do any of the work and can "audit" the course if you like or you can complete it and get a certificate (for most).
Anyway, I figured I'd share a few interesting ones in here in order of when they start:
Algorithms, Part I
https://www.coursera.org/course/algs4partI
Cryptography
https://www.coursera.org/course/crypto
Functional Programming Principles in Scala (Taught by Martin Odersky)
https://www.coursera.org/course/progfun
An Introduction to Interactive Programming in Python
https://www.coursera.org/course/interactivepython
More here:
https://www.coursera.org/courses