Just as President Barack Obama's campaign reached out to a new generation of viewers, TV networks used social networking sites like Twitter and Facebook to speak to that same audience on Inauguration Day -- and to let them talk back.

In a special "Inauguration: Shout Out," Current TV carried yesterday's ceremonies live, combined with a steady stream of comments from Twitter users.

Current, founded by former Vice President Al Gore and businessman Joel Hyatt, is a cable/TV/Internet platform aimed at younger viewers. The Twitter messages appeared on its TV broadcast, enabling those without an Internet connection to experience the phenomenon.

"Yes, we did :-)" was a "tweet," or message, from one Twitter user that summed up the overflow of optimism and emotion that users posted to a global audience yesterday.

CNN carried a live video stream of the ceremonies on its Web site, accompanied by running comments from Facebook members, who could log in and see what their network of Facebook "friends" was doing and saying, or check out a wider collection of comments.

Twitter and Facebook messages came from across the country, and sometimes in other languages from all over the world, illustrating the worldwide scope of the event and its media coverage.

They ranged from the engaged, especially the instant reactions to Mr. Obama's inauguration speech as it was happening, to the emotional ("OMG, I'm going to cry!") to the mundane ("I have never seen Spielberg so well dressed.") The chatter took a sometimes nasty turn during coverage of former President George W. Bush's helicopter takeoff.

Others used the Facebook and Twitter posts to document the experience of watching history unfold in a new media world: "Now have CNN, MSNBC and Monitter going … woo woo! Anybody 'working' today?" Others noted technical glitches they were experiencing as millions explored various Internet sites.

And a few seemed to be experiencing information overload: "Too much inauguration coverage, I'm just gonna listen to the speech later."

CNN kicked its use of technology up a notch in other ways for the big day, with the creation of a giant 3-D image of the National Mall at the moment the new president was sworn in.

The image was created using photos submitted by people who captured images of the event with cell phones and digital cameras. CNN, in partnership with Microsoft, used Photosynth technology to stitch these photos together.

It was televised and also posted on the network Web site, where users could explore it and look at it from different angles in what CNN Washington bureau chief David Bohrman called a "real user-generated moment of history."

CNN used similar technology during its 2008 election coverage, when a tomogram (a projection similar to a hologram) of reporter Jessica Yellin, who was in Chicago, appeared to be in the New York studio talking with anchor Wolf Blitzer. It also was used with anchor Anderson Cooper talking to the image of hip-hop artist will.i.am.

The three major networks carried a live Webcast of the ceremonies, and many radio stations carried video or audio streams on their Web sites as well.

The PBS site for "The News Hour With Jim Lehrer" used an interactive map to steer its audience to what was happening and when, and also had photo and text updates via Flickr and Twitter, respectively

The online coverage had its glitches. Video streams were often choppy and slow. At some points, the CNN feed looked more like a slide show, with a slow-moving sequence of still images.

Latecomers or people whose systems crashed while they were watching couldn't get back on to the CNN site. Instead they received a message that they were in queue until openings came up. Facebook members were able to access the CNN stream through Facebook, however.

Technical problems had been anticipated, due to the sheer volume of traffic expected online. CNN Worldwide reported that by 11:45 a.m. yesterday, just before the swearing-in ceremonies, CNN.com Live had served 13.9 million live video streams globally since 6 a.m., breaking its previous Election Day record of 5.3 million streams.

Even sites not geared to daily news coverage streamed the event, including Web TV sites Hulu, which carried Fox News' video stream, and Joost, which carried the CBS stream, along with the Internet Movie Database. Even BettyConfidential.com, a news and lifestyle site targeted to women, got into the act with behind-the-scenes video coverage of the ceremonies, balls and other events.