Website Lets You Into Harvard—Free

No notes, no homework, and you can wear your PJs the entire time you "sit in" on Harvard classes—online. Academic Earth's online classes are "unexpectedly irresistible," Farhad Manjoo writes for Slate. "It's like Hulu, but for nerds." The company's collection of videotaped lectures from schools like Harvard, Yale, and Stanford is a "geeky procrastinator's dream." Participants can search classes by subject and even get access to course handouts and transcripts.

The video quality is generally good, but sometimes it's hard to hear student questions, Manjoo writes. Another downside: There are tons of science and economic courses, but not a lot of humanities offerings. "Academic Earth is more of a pastime than a replacement for college," he writes, but you can't beat listening to "the world's experts talking about stuff they're passionate about."