Plaxo Personal Assistant will monitor the public Web for updates on your contacts.

This review has been updated throughout, now that I have had hands-on experience with the Plaxo Personal Assistant product.

Some time after its launch back in 2002, contact list management app Plaxo lost its way. Leadership at the company saw social networking as a bandwagon it had to get on and made Plaxo into a personal social hub--which nobody really needed. It was the second bad mistake Plaxo had made with its service, the first being its habit of sending requests for updated information to users' contacts that were often taken for spam. Nobody liked Plaxo's users, even though Plaxo's core address book updating and multidevice sync functions were quite useful.

Now the company, a division of Comcast for the last three years, is going back to its roots as a contact updating and synchronization service, which is still a needed function. If you've got different and conflicting address books on the Web, your e-mail app, and your phone, then you know the problem well. The new Plaxo also dials back on the outbound e-mails, so you can use it without becoming a pariah. But it's facing off with a less well-known competitor that performs a similar function for 100 percent less money.

Plaxo is officially dumping the redundant social-network portal today and launching a new service to automate address book maintenance for its users. The new Plaxo Personal Assistant takes your personal address book and goes out to the public Internet to find updates for the information in it. Then it syncs that data back to your existing address books (on Outlook or Google) and devices (iPhones and so on).

Unlike Hiya (see review below), which uses White Pages data to update home addresses and phone numbers of your contacts, Plaxo uses ZoomInfo to update business contact details, like the companies your contacts work for, and their titles and work contact information. That's of more business use, obviously, than White Pages data. And having the data updated automatically means you don't end up annoying your contacts with impersonal impingements on their time. You won't get unlisted and private information, of course, but you will get to keep your friends happy.

I was also not willing to experiment with Plaxo's sync function to send its data back to my main contact list on our company's Exchange server. As is the case with many people I know, my own address book is made from a collection of separate and fragile lists in various Exchange folders, plus some iPhone-only addresses. As much as I would like to pull all these lists together, Smalley told me I'd have to disable existing Exchange sync functionality on my phone, and also install software on my PC, to sync with Outlook directly to make Plaxo work, and we weren't sure all my data would make the transition back to Exchange. I did connect my Plaxo account to a Gmail account, and the two-way synchronization was fast and accurate.

Plaxo's best features are not cheap. The new automatic update feature, Plaxo Personal Assistant, is $79.95 a year. The sync tool, Plaxo Platinum Sync, is also a paid service, at $59.95 a year. You can get both for $120 a year (a savings of $1.66 a month, if you're counting). Plaxo is a useful service, but these are high prices. Someone who's concerned enough about contact maintenance is probably already paying for LinkedIn (starting at $239.40 a year) and possibly an e-mail intelligence app like Xobni Plus ($95.88), both of which you're more likely to use day-to-day.

Plaxo does have a useful free function that it used to charge for, a de-duper to get rid of the dust bunnies of modern address books: the repeated contacts that come from the contact list merges we do from time to time, such as when moving to a new mobile device. This tool works well, merging data appropriately from separate records, and always asking before performing a merge that may not make sense. The de-duper is a key feature given Plaxo's focus on merging and synchronizing contact lists from multiple sources (Outlook, Google, smartphones, etc). Plaxo will collate your address books from all your sources, and merge them into one online address book (at Plaxo.com) for free, which is good for backing up your personal contact lists. But it is the paid services that make Plaxo really useful.

Hiya also updates contacts from public information--but it&39's free.

If you don't want that, try this There's a serious competitor to Plaxo, called Hiya. Like Plaxo, it will de-dupe your contacts and update them automatically from public White Pages data. I fed Hiya my iPhone address book, and it did a good job at finding and merging duplicate contacts. It also put personal (home) contact information that I didn't have into my address book. Hiya doesn't, though, know much about contacts' work information, as that data isn't in phonebooks. For keeping business contacts up to date, Plaxo Personal Assistant does a better job.

As with Plaxo, though, a flaw in the system meant I couldn't sync my changes back to my iPhone address book. In Hiya's case, I was alerted that enabling two-way sync would replace all the photos in my iPhone address book (and by extension my synced Exchange contacts) with blanks. That wasn't a feature I wanted.

Hiya does not work directly with Outlook or Exchange, but if you enable two-way sync to your iPhone, you can update your PC-based addresses indirectly. It will connect to Google Contacts, though. It will also, if you ask it to, e-mail your contacts asking for updated contact information. Plaxo has taught us that people dislike receiving those e-mails.

One big advantage: Hiya is free. I like its iPhone app, too.

There's a big limitation in both Hiya and Plaxo: Neither uses Facebook or LinkedIn as a source for updating contact info. These social networks are the de facto white pages of today's Internet, so it's a shame that these utilities don't use them. I'm told that in the case of Facebook, it's because that service doesn't allow API calls to the address book (for once, Facebook is more private than it should be)' Hiya representatives tell me that Facebook integration is coming, though.

Recommendations (updated) For people who want to keep their address books updated with personal information on their contacts, Hiya is a good address book management utility. It's free, easy to use, and does a good job with de-duping and filling in information. Plaxo is better for automatically updating business contact information, but you'll pay a lot for the service. Plaxo also remains the go-to updating service for users who are primarily on Outlook. It's a shame neither service does a complete job, updating both personal and work information accurately.

Anyone with an older or complicated address book scheme should proceed with caution, however, as neither system has perfected the mechanism to sync updated contact lists back to PC- or phone-based address books.

See also Soocial, which does sync and de-duping.