GoodContacts Solo 3.1 for Outlook and Plaxo Contacts take different tacks in managing and updating your Outlook address book. But ultimately both reduce the complexity by e-mailing people in your address book to ask for updates and by sending out your updated information as well. GoodContacts is more versatile and better suited to business users with thousands of contacts. Plaxo integrates with Outlook and is ideal for budget-conscious professionals with small address books.

Unlike GoodContacts, which routes your updates through its servers, Plaxo provides a direct exchange of information between you and your recipients. The makers of both products pledge not to market or share any of your data, and both take extensive precautions against hackers. Each company is trying to build a peer-to-peer network of users who will benefit from automatic contact information updates among members. The products will realize their true potential, though, when you can do more than exchange contact information and when they support a wider range of e-mail options—Web mail services, AOL mail, and Outlook alternatives like Lotus Notes, for example.