Did you know that college and universities around the world post courses online that you can take for free?  Better yet, several websites exist that aggregate these courses, filter the best ones, and help you find subjects you're interested in learning.

Here are a few the leading college course websites:

• AcademicEarth.org:  Offers courses from 10 elite universities, including 130 full courses and more than 3,500 video lectures.
• Connexions (cnx.org): More than 16,000 learning "modules" that are organized into nearly 1,000 learning collections (such as a statistics course).
• OpenCourseWare Consortium: 13,000 members post materials and lectures from 250 universities worldwide.
• OpenCulture.com: Director of Stanford's continuing education program has gathered 2,700 audio and video lectures from more than 25 universities.
• YouTube.com/edu: The popular video portal offers 200 full courses and 60,000 videos from about 300 colleges and universities.

Such courses are great for adult learners who wish to expand their horizons without a formal university program.  But these courses are also helpful for college-bound high school students who can get a taste of what a college course is really like before even setting put on campus.  For such students, it's also a nice way to test drive if an academic field is something you might be interested in pursuing as a degree.

Have you found a college course online that you really like?  Post a comment below and let me know!