Gödel, Escher, Bach
Links (videos): OCW (RealPlayer)
Links (additional): Course Home Page
Review: This is a summer course for high school students taught by a couple MIT undergraduates (Justin Curry and Curran Kelleher). This is actually a very good course, specially considering the book it is based on is quite challenging. While the lectures aren't (by any stretch) a replacement for Douglas Hofstadter's book, they are a wonderful aid for getting started with the book.
Donations/Home Pages: MIT OpenCourseWare