People are spending more time in front of their computers than ever, thanks to surging demand for broadband services and offerings such as Internet video and photo sharing.

The average PC user spent 30 hours in front of his box last month, according to Nielsen/NetRatings, up from 27.5 hours a year ago. In addition, Nielsen/NetRatings estimates that the number of active broadband users in the U.S. jumped 28% to 95.5 million.

"The correlated growth in average PC time per person is the result of broadband users' greater satisfaction with their online experience," says Jon Gibs, senior director of research at Nielsen/NetRatings. "The 'always on' nature of a broadband connection allows the Internet to become more entrenched in consumers' lives."

Internet service providers including Comcast ( CMCSA) and Verizon ( VZ) are using special offers to get people to switch from slower dial-up service to broadband.

About 68% of all active Internet users have broadband service, Nielsen says. That's up from 55% a year ago, continuing a pattern that's been seen over the past three years, the research company says. Increased broadband use is leading to a surge in use of sites such as MSN Video , which had a unique audience of 9.3 million users in February, surpassing rivals including YouTube and Google Video , according to Nielsen/NetRatings.

Web video is attractive to advertisers, who are becoming increasingly picky about where they spend their money online, because it attracts users that seem particularly interested in the content. That's why portals including Yahoo! ( YHOO) and Time Warner's ( TWX) America Online are expanding their video offerings. Time Warner is hoping to further capitalize on the craze through its new humor site Office Pirates .

"Video sites have successfully tapped into the use of viral campaigns, capitalizing on consumers' impulse to share funny clips with their friends," says Nielsen/NetRatings' Gibs. "Among these sites it is not uncommon to see dramatic spikes in weekly Web traffic due to a popular online video that has been sent from person to person."