PHILADELPHIA — A tap on the HealthMap iPhone application brings up a cluster of red pins on a map, representing nearby cases of swine flu. Another tap brings up a form for ordinary Americans to add to the collection by reporting bouts they have or know about.

HealthMap Outbreaks Near Me is among scores of iPhone apps, along with social networks, Wikipedia and flu-tracking sites, that give consumers new ways to share information, shape conversations and keep tabs on swine flu and other health threats like it.

With instant two-way communication unavailable during past pandemics and smaller outbreaks, the public now can help paint a fuller picture of what's happening and complement the often delayed and restrained notices from health officials.

And though swine flu infections have been waning since October, the apps and other digital tools have transformed the way such health crises will be tracked in years to come. They offer a window into the opportunities — and dangers — that come with the rapid spread of information from everyday people.

Ultimately, these tools may be no more than a fun way for people to connect — not entirely useful, perhaps even misleading.

Still, the more than 100 swine flu apps for Apple Inc.'s iPhone, either free or for a fee, may mollify some concerns people have about health outbreaks because people don't like to be kept in the dark too long.

Take HealthMap Outbreaks Near Me, which has been downloaded more than 100,000 times. By learning of outbreaks, a user can take preventive measures, such as getting a vaccine or washing hands more diligently.

The new strain of the H1N1 virus, also known as swine flu, claimed more than 11,000 lives and required the hospitalization of some 250,000 people. If such an outbreak can be identified quickly, people could be warned about it sooner and help limit its spread.

Mark Peterson, a 23-year-old iPhone app developer from Newark, N.J., created Swine Flu 101 to provide the latest news and a state-by-state list of cases and deaths.

Add to that all the streams of data coming through social networks and other means. Twitter said "H1N1" is among the 50 most tweeted topics of all time.

Swine flu "is the first pandemic to use digital tools," said Ann Aikin, a social media strategist at the Centers for Disease Control and Prevention.

Whether these efforts prove useful is another matter. "In general, having more information is better than less," said David Bell, a marketing professor at the University of Pennsylvania. But there's a danger that "the information gets transmitted over and over and the story changes."