You might already know about Kahn Academy which provides an interesting and fun way of learning for children up to around a high school level. But what do you do if you are an adult and want to learn a more advanced topic. If you are not the person that is able to get comfortable with a new field by just picking up a book. There is another site aiming for revolutionizing higher level education in the same vein as Kahn Academy is trying to do for lower degrees called Udacity.
Currently the site is free as they are building up their course catalog, but the goal is to eventually offer the equivalent of graduate degrees for as little as $100. A slight difference to what is currently available from universities in the US.
They are also disputing the notion that learning that happens early in your life before you go off and start your career. Instead it thinks that you should keep educating yourself throughout your entire life. Something that I totally agree with.
I completed a couple of classes myself and so far I really like it and can completely recommend it to everybody who has an interest in learning new things. And as I said earlier... It's free!