I can't even tell you how much I have learned outside of school and work by working on an outside project.

I had a co-worker ask me "How do you code so well in C#? I want to be a master in that language."

My reply... "Create a simple blog project and then work from there. Eventually you'll want to add more and more features that will move you throughout that chosen language."

I've learned so much by creating and uploading semi-unfinished side projects on the web.

e.g. artJutsu.com/lightbox