The crash of U.S. Airways Flight 1549 is just one of the latest examples showing how platforms such as Twitter are evolving beyond social messaging services into interactive news sources that corporate executives have to consider and monitor in their communications programs.

Almost immediately after Flight 1549 slid safely into the New York’s Hudson River, the first announcements of a plane crash appeared on Twitter. The first image of the crash, depicting evacuating passengers waiting on a wing, was posted by a passenger on a ferry boat hastily recruited to serve as a rescue vessel.

Within an hour, thousands of short messages relayed news and images of the event, re-posted links and updated news accounts, and shared toll-free numbers for information about passengers. Major news organizations were harvesting tips from the stream of Twitter messages as well as using it to provide updates and links to their coverage.

By the time the airline issued a statement on its Web site an hour after the event, the release was largely ignored by an audience already engaged in the Twitter coverage.

Although Twitter cannot be described as a mainstream service yet — varying estimates place its user base at about 2.5 million — it is reaching an Internet-savvy audience that feels a need to always feel connected.