AOL is undertaking the project with Plaxo, a.
The move comes as Internet service providers such as AOL, Yahoo, Microsoft's MSN and Google fight over who can best help people manage storehouses of personal data online.
As part of Wednesday's deal, America Online plans to include Plaxo's personal information management tools in free upgrades of AOL's core Web services and its AIM instant messaging system.
The goal is to keep 40 to 50 million active AOL and AIM members current on the ever-changing personal details of friends and associates by giving AOL users and their contacts greater control over how their personal data is shared.
Plaxo offers Web users a way to keep track of not just phone numbers, e-mail and text message addressees, but physical locations, IM screen names, Web-calling services and other ways of communicating within one's own personal network.
By plugging Plaxo features directly into its own services, America Online will offer subscribers a unified way to keep track of their contacts.
"This deal is about trying to give AOL users more control over how they interact with all the people they know and having a sense of control over all those details," said Charles Golvin, an Internet industry analyst with Forrester Research.
Plaxo has won an avid following among a technically adept crowd of more than 5 million users of Microsoft Outlook and other Web-based information management programs who use Plaxo to stay in touch with business associates.
The America Online deal will offer a sophisticated new level of personal data control to a far wider consumer audience as AOL and AIM users upgrade to new software that embed Plaxo features later this year, officials of the two companies said.
Currently an estimated 33 million AIM users trade instant messages with lists of buddies. AOL counts 28 million active subscribers to a range of interactive services.
By offering subscribers a more convenient ways to stay linked with their contacts, AOL hopes to encourage loyalty from customers. It also hopes to become relevant to a wider Web audience of non-AOL users through its subscribers' own address books.
Plaxo takes advantage of a basic feature of instant messaging known as "presence indication"--small icons that change color depending on whether a computer or mobile phone user is available online, away, "out to lunch" or signed off.
Presence indicators glow when a person is available on some services or signed off of others, simplifying how one can locate a contact in the way the other wishes to be contacted.
"It really is giving AOL members a sense of what 'always on' and 'always available' can mean," said Chamath Palihapitiya, general manager of AOL's AIM and ICQ instant message services. "This empowers users to control how they communicate."
By giving individuals the tools that can help them limit how much information they release to others, the AOL-Plaxo service also addresses concerns in the United States over identity theft.
Plaxo allows individuals to say when and how and by whom they can be contacted--and to change their mind later on whether to let contacts update their personal data.
"Some people want to know every connection that people know about them," Plaxo Chief Executive Ben Golub said. "Some people are less concerned and will want to share their business card with the world, while tightly controlling details of their personal life," he said. "We let you control that."
Golvin added that mobile phone and broadband services also are angling to help consumers consolidate their personal data.
Plaxo already offers a set of it tools to Yahoo users for synchronizing address books and calendars found in applications like Microsoft Outlook or Outlook Express with Web-based address books offered by Yahoo. The AOL deal goes further by embedding Plaxo across AOL services.
"There's a brewing battle over address books," he said.