Called The Crawl at MSNBC and CNN, and the "News Crawler" at Fox, the feature evokes the famed news zipper on New York's Times Square, which has operated since November 1928. Crawls are typically a feature of local news stations coping with a natural disaster like a hurricane or an earthquake. But since September 11, the cable networks have found it an effective method of delivering headlines about the investigation, pending military action and ongoing recovery to a news-hungry nation. "Someone had a good idea to improve our coverage and so we went with it," says David Rhodes, who oversees the crawl as the assignment manger at Fox News.

The crawls are another example of the increasing segmentation of the TV screen. Network logos in one of the lower corners of the screen are commonplace, for instance. Other onscreen banners and headlines on news shows make the television seem more like a computer screen -- chief among them CNN's redesigned Headline News, which rankled traditionalists by filling the bottom third of the screen with rotating headlines, a weather map and even promos.

None of the channels expects the crawls to disappear anytime soon. Although the crawls no longer carry crisis updates, they still have all the ongoing news about the national emergency. They foreshadow stories that will soon get airtime and, conversely, show developments that the larger screen will ignore. It's the only way to handle the torrents of news, say network executives. "As long as we think there is enough information on this story that is worth feeding people, we'll have it up for awhile," says Ramon Escobar, executive producer at MSNBC. "There's just a flood of information."

The crawls focus not only on the attacks –- they're often an outlet for information eclipsed by the terrorism coverage. "Some things in the ordinary news environment that would have merited more coverage elsewhere on the screen was relegated to the crawl, like Michael Jordan coming back," says Rhodes. "We can inform people and not take away from any information on the terrorist attacks."

Fox's crawl has 70 or so headlines cycling through, which takes 10 minutes to turn over. The network operates the service from the assignment desk, which manages the camera and mobile crews. Since most of the news from the field flows through the assignment desk, whether it's from Pakistan or the State Department, the assignment desk editors responsible for transmitting news between producers and crews also update the crawl. "It's a process where editors have screened reports, disseminated them internally and also are passing them along [through the crawl]," says Rhodes.

MSNBC's crawl, which has between 30 and 50 headlines, is run solely by a news producer dedicated to the task. The producer reads all the internal and wire reports and enters the information in real time. The crawl is updated from 8 a.m. to 1 a.m., after which it remains unchanged for seven overnight hours unless news breaks. "An overnight team can change it if there is dramatic change or development," says Escobar.

CNN wasn't able to provide an executive to discuss their crawl techniques.

Fox News enjoys reminding folks that it beat its rivals to the crawl. "In this story, we definitely did that effect before the rest of them," says Rhodes. "I wonder what else we could put up on the screen that they would also copy."