Want to master a new computer language? Brush up on your calculus? Learn how to fix your car? No sweat. With the vast array of college courses and podcasts available online, the apple of knowledge is ripe for the clicking. Here, we've narrowed the options to our favorites–the best of the geeky best, from free podcasts and lectures to accredited distance-learning programs from major universities.
UNIVERSITY EXTENSION PROGRAMS:
What Is It? Similar in philosophy to open-source software, OpenCourseWare offers anyone free access to course materials for virtually all of MIT's undergraduate and graduate courses. Once upon a time, you needed at least a library card to get a free education. But with this site, you can get rocket-scientist smart without even paying late fees.
Why's It Cool? This is a site for people who enjoy the pure pleasure of learning. You won't get credit for any of the course work-in fact, you won't even have access to teachers-but if you're a self-starter and curious, you can dabble in any of the subjects that MIT offers.
Can't Miss? The sheer volume of subjects available is stunning. The site offers course materials in everything from aeronautics to biological engineering to linguistics.
What Is It? The Harvard Extension School provides access to roughly 100 online courses in art, science, math and technology, all from the comfort of your couch. Upcoming fall courses range from an introduction to Greek literature to a variety of Web-development classes.
Why's It Cool? These courses bring students right into the classroom with video lectures that are posted along with the other course materials. Bonus: Distance learners are always welcome to drop in on the real lecture if they happen to be passing through campus.
Can't Miss? For a sneak peek of what these courses are like, a few sample lectures are available online.
What Is It? The school offers more than 250 courses in subjects ranging from bioengineering to nanotechnology. Coursework is delivered through a variety of mediums, including the Internet, television broadcast, videotapes and two-way video. Scientists and engineers flock to this program to enhance their professional skills.
Why's It Cool? The classes fit a wide variety of educational needs. Students can enroll in short courses and seminars aimed at improving skills in specific areas, or they can sign up for the long haul with certificate programs and even graduate-degree programs.
Can't Miss? Instructors include some of the crme de la crme of Stanford's school of engineering.
What Is It? Whether you're a coding novice or an open-source enthusiast, the O'Reilly School of Technology has a class in Web development to suit your needs, including HTML, Linux/Unix, Java and XML, to name just a few. The school also offers certificate programs in a variety of subjects like Linux/Unix system administration and .NET programming. Students gain credits through the University of Illinois Office of Continuing Education.
Why's It Cool? Course materials dispense with convoluted tech-speak and instead go for a casual, fun tone that makes the information easier to retain.
Can't Miss? Anyone who uses the Internet regularly could benefit from learning HTML. The "Introduction to HTML and CSS" course fits that bill perfectly and provides a great base for moving on to more complicated classes.
What Is It? This granddaddy of online math programs has been helping home-schoolers, university kids and professionals put two and two together since 1991. The school's offerings include algebra and trigonometry, analytic geometry, and calculus for business. Students receive credits from the University of Illinois, an accredited Big Ten university.
Why's It Cool? With a holistic learning approach that engages the whole brain (including the part that likes to have fun), NetMath takes the "I want to jump out the window" out of math class. Each course incorporates interactive software that gives students a more exciting and memorable way to learn than old-school, one-dimensional textbooks.
Can't Miss? The program uses Mathematica software to help students visualize abstract algebraic concepts.
What Is It? You can become your own grease monkey with this professional-level auto repair course. The program offers a series of 20 lessons that teach everything from engine assembly to fixing a car's heating and air conditioning systems.
Why's It Cool? The lessons are just as well suited to the auto enthusiast who wants to tinker in his own garage as it is to pre-professional mechanics.
Can't Miss? The tools-this course comes with lots of 'em. Included in the cost of the class is a wrench set, socket wrench set, screwdrivers and tire gauge.
What Is It? Penn Foster offers a sequence of classes designed for people who want to become PC-repair technicians. The courses will teach you how to repair PCs, printers and PDAs, as well as cover PC operating systems and data recovery. Sick of calling in the professionals every time your PC crashes? Complete this program, and you'll be able to do it yourself.
Why's It Cool? You don't need to be a computer whiz to take these classes. The first lessons teach the basics of computer language and the fundamental elements of hardware and software-all at a pace you can set yourself.
Can't Miss? If you're actually looking to switch careers and become a full-fledged PC repair technician, the Penn Foster Career School will help you find a job.
What Is It? NASA's experts bring you this fun, free series of audio shows on flight, space and a range of other subjects pertaining to the solar system and the universe.
Why's It Cool? Think you're signing up for a sleep-inducing audio lecture? Not so: These shows are pure edutainment. Load them onto your iPod, and learn a little something during your next long commute.
Can't Miss? Check out the program on the power of acoustics and resonance, in which country musician Clint Black explains how his guitar is like a rocket.
What Is It? This weekly podcast reaches for the stars, covering everything about astronomy, from cosmology to Castor and Pollux.
Why's It Cool? The hosts of each episode, Fraser Cain (from Universe Today) and Pamela L. Gay (from Southern Illinois University Edwardsville), are entertaining and well-informed.
Can't Miss? Be sure to download episode 31, "String Theory, Time Travel, White Holes, Warp Speed, Multiple Dimensions, and Before the Big Bang," in which Gay disproves most of the theories behind science fiction.
What Is It? The Canadian Broadcasting System presents its popular Quirks and Quarks science radio show in the form of a podcast. Recent episodes have included segments on crayfish sex, the future of human evolution, and water on Mars.
Why's It Cool? The Canucks know their science, and they're great at picking out topics that make for good cocktail-party conversation-you know, the quirky ones.
Can't Miss? One episode suggests that we might reduce global warming with an Earth "sunscreen."
What Is It? The BBC presents this weekly podcast, hosted by researchers at the University of Cambridge.
Why's It Cool? The hosts are funny and the subject matter is always engaging. The whole family will enjoy hearing about topics like venoms and toxins, out-of-body experiences, and Armageddon-like natural disasters.
Can't Miss? The episode on extreme survival is about how different life-forms-fish in Antarctica, divers in the ocean, and fighter pilots high in the sky-endure dangerous environments.