Content from Al Gore's Current TV will begin streaming on the newly launched Yahoo Current Network, which is targeting the 18-34 demographic.

Gore hopes to expand Current TV's audience beyond cable, where the network's reach is 30 million, a low figure by TV standards - and too low for Nielsen to rate, reports Business Week. Yahoo Current Network will feature four channels of streaming video, and Gore's Current TV will supply content - both professional and amateur videos.

Most clips will be preceded by a 15- or 30-second ad - the first time that Yahoo has included commercials with user-generated content, writes the New York Times. The four Yahoo Current channels cover topics favored by advertisers: news, travel, action sports and cars. More are planned.