Plaxo turns address books into Web social networks

In a major comeback push by the 6-year-old company, which Silicon Valley insiders see as a forerunner of the social-networking craze, Plaxo has created the first Web service to share data between major address and calendar programs.

With Plaxo 3.0, as the new service is known, consumers can synchronize address books and calendar data locked up inside Microsoft Outlook, Google and Yahoo services, Apple Macintosh computers, Mozilla Thunderbird e-mail and many mobile phones.

Now Plaxo is going head to head with social networks, which, rather than forming links between computer address books, link people online through their shared media interests--based on what they write or the photos and video they choose to share.

Plaxo plans to let friends keep track of their contacts' Web-surfing habits, paralleling a feature fueling the rapid rise of Facebook, which allows users of all ages to create private networks to connect to their immediate friends. Watching and learning what your friends are doing on the Web--and being watched yourself--is today's hottest online trend.

"The most important things happening right now on the Web are about people's relationships with other people," Chief Executive Ben Golub said in an interview. "There is no reason to segment your relationships with others based on which applications you use."

Plaxo previously enabled individual users to stay in touch by automatically sharing data between contacts' address books. It has signed up more than 15 million registered users to date, although the number of active users is unknown.

Plaxo functions like a network of address books. When a phone number of someone's contact changes, it automatically updates in contact address books, assuming that the contact gives permission via e-mail.

"We tackled the hard problem of making synchronization that just works," Golub said. "Our role in this is to be the Switzerland of personal information."

The move involves synchronizing all the scheduling and address information an individual has scattered across computers, mobile phones and online accounts, and linking up this data to personalized Web pages so that friends can stay abreast of Web activities the user lets them know about.

"He who syncs best, wins," JupiterResearch analyst David Card said. "It's not something you can get from Google yet. Plaxo's approach has got good potential."

Plaxo Pulse, as the social-network profile site is called, uses Really Simple Syndication (RSS) feeds to pull in Flickr photos, blog posts, Amazon.com Wish Lists, and Plaxo contact changes from friends who permit sharing personal information.

Plaxo 3.0, in public test mode, is the result of a quiet yearlong reworking of Plaxo software. It is available in seven languages--English and, for the first time, versions in French, German, Japanese, Portuguese, Simplified Chinese and Spanish.

Instead of needing to download Plaxo software to one's computer or phone, Plaxo 3.0 is delivered as a service over the Web.

In a twist on the notion that all humanity is connected by only six degrees of social separation, Plaxo has aimed to organize users' ties to people in real life--those in one's address book--while social networks connect their users to second and third-level connections--friends of friends.

Plaxo 3.0 can connect Google Calendar (and shortly Gmail's address book) with Microsoft Outlook, Outlook Express, Vista Mail or Hotmail, Yahoo Mail and Calendar, Apple services such as iCal and Address Book, AOL Instant Messenger and LinkedIn Premium version.

For mobile phones, a WAP 2.0 version of Plaxo for phone browsers is available.

U.S. CDMA mobile phones--including those of Verizon Wireless and Sprint--can download Plaxo. Over the next several months, modern Java-based handsets from mobile operators such as AT&T and T-Mobile will be ready to run Plaxo. Mobile phones from international operators will also follow, officials said.

The Plaxo service is free. A premium version that costs $49.95 per year offers features like automatic data recovery and eliminating duplicate contacts, company executives said.

Plaxo has taken $28 million in funding to date from backers, including Sequoia Capital and DAG Ventures.