The Internet is known for giving power to the people. Sites like YouTube and Wikipedia collect the creations of amateurs and kick pros to the curb. But now some of the same entrepreneurs who funded the user-generated revolution are paying professionals to edit and produce online content. In December, Google began testing Knol, a Wikipedia-like Web site produced by "authoritative" sources that share ad revenue. A sample page contains an insomnia entry from Rachel Manber, director of Stanford's sleep center. In January, Big Think.com, a self-styled "YouTube for ideas" backed by former Harvard president Larry Summers and others, debuted its cache of video interviews with public intellectuals. Mahalo also just launched a test version of its people-powered search engine, which replaces Google's popularity-based page rankings with results that the start-up says are vetted by real people. In a search on "Paris hotels," Google returns 5 million pages from an array of obscure Web sites. Mahalo gives you a list of seven big-name sites, including Frommer's, Fodor's and Lonely Planet. Mahalo's lead investor, Sequoia Capital, was also an early backer of YouTube, Yahoo and Google.