Asking students to discuss their classes in a very public forum has got to raise concerns for some people as well. Rankin says participation isn't required, but it's because of these kinds of concerns that private, education focused services like EdModo have a market. That closed communication comes at the expense of public knowledge sharing, but classroom innovators may not be able to have it both ways in the long term.

In other cases, the same digital economics have spurred entirely new business models, such as "Freemium," a free version supported by a paid premium version. This model uses free as a form of marketing to put the product in the hands of the maximum number of people, converting just a small fraction to paying customers. It's an inversion of the old free sample promotion: Rather than giving away one brownie to sell 99 others, you give away 99 virtual penguins to sell one virtual igloo. (Confused? Ask a child: This is the business model for the phenomenally successful Club Penguin.)

The explosion of all types of video content on YouTube and other sites is quickly transforming online video from a medium strictly for entertainment and news into one that is also a reference tool. As a result, video search, on YouTube and across other sites, is rapidly morphing into a new entry point into the Web, one that could rival mainstream search for many types of queries.

And now YouTube, conceived as a video hosting and sharing site, has become a bona fide search tool. Searches on it in the United States recently edged out those on Yahoo, which had long been the No. 2 search engine, behind Google. (Google, incidentally, owns YouTube.) In November, Americans conducted nearly 2.8 billion searches on YouTube, about 200 million more than on Yahoo, according to comScore.

“Is YouTube the next Google?”

netTrekker d.i. wants to send you to NECC '09 in Washington, D.C. June 28-July 1! We understand the difficulties with funding concerns and cutbacks for out-of-state travel. We want to help! netTrekker d.i. will award two $1500 scholarships to assist educators with conference registration, travel expenses, etc., to NECC '09.