Recently a friend asked me to take an online course with him. Although I'm a big proponent of education, I didn't see the value in taking a couple extra classes. But I begrudgingly enrolled because the classes that seemed interesting in AI & search engines. I was very surprised at how well done the entire class was, how easy it was to follow each exercises and do homework functioned online. It was very easy to fit it in my schedule too. Sections are given out each week at your own pace, so I was able to go through them at various evenings during the week or on the weekend.
Another great online education resource is MIT OpenCourseWare which provides 1,000's of their past years courses online in several subjects so you can sharpen your calculus skills, study history, or learn about Chemical Engineering Thermodynamics.
"I don't always take classes, but when I do, I prefer Udacity & MIT online courses. Stay young my friends, and keep your minds fresh."