NEW YORK - In an inauguration defined by a sense of change, the experience of watching Barack Obama take office was fittingly revolutionary.

Like never before, Americans watched the inauguration of an incoming president online through live video streaming across their computers. And wholly wrapped up in following Inauguration Day 2009 on the Web was reacting to them - blogging, vlogging and tweeting.

Essentially every major news outlet offered live feeds on their respective Web sites in what was potentially the most Web-driven coverage of a significant news event yet. It was partly out of necessity, since many viewers were at work in front of their computers - and away from TV sets - for the midday swearing in.

It was also a notable benchmark in the fast evolution of online video. At the time of the last inauguration, YouTube didn't even exist.

The major news portals - Yahoo.com, CNN.com, MSNBC.com, AOL News, The New York Times, ABC.com, CBS.com, Fox.com, WashingtonPost.com - all streamed the festivities, some with video embedded right on their home page for the first time.

Akamai Technologies Inc., which delivers Internet video for many Web sites, said the inauguration was a record for them, with 7.7 million people watching video streams at the same time.

So much video meant bandwidth was stretched considerably for many sites and many servers. On the whole, the webcasts appeared to function well, albeit with some lags.

Keynote Systems Inc., which tracks Web site performance, said the Internet's top 40 sites slowed down by as much as 60 percent when the ceremony started at 11 a.m., and many news sites saw even sharper declines in performance.

Many sites streaming the festivities gave four different perspectives on the ceremony, giving the viewer the option of watching the primary feed, the crowd amassed along the Mall or other views.

Several outlets looked to combine traditional coverage with new media interactivity.

CNN partnered with Facebook (for users of the social networking site) to include status updates from friends alongside the webcast. The result was that it (kind of) felt like you were watching along with your friends.

As of 3:30 p.m. EST Tuesday, CNN.com said it served more than 21.3 million live streams globally since 6 a.m. That was nearly four times the amount of live streams on the site on Election Day when there were 5.3 million lives streams.

Mimi Wong, a 28-year-old public defender from Brookline, Mass., watched the CNN.com webcast at work with her colleagues.

"It was pretty cool," said Wong.