At first glance, Plaxo looks a lot like Microsoft Outlook.  If you are a Microsoft Office user, Outlook and the home-use Outlook Express both provide many of the same contact management and calendar features.

Plaxo focuses on bringing together professional and social contacts into a single list, available from any computer or web-enabled phone.  Do you use Google GMail?  Plaxo easily brings in those contacts as well as those you may have in an email program at your workplace.  Macintosh users can upload their OS X address books as well.

As an online networker, consider investing a few minutes to input your Plaxo profile.  This builds a nicely-formatted showcase for experience, skills and interests.  With a few additional clicks, you can configure your Plaxo.com home page to bring in updates from contacts followed on Twitter or friended on Facebook.

Now you have an easy way to expand your network of contacts.  From the Plaxo home page, click any name from the Twitter and Facebook messages.  This brings you to status updates, contact information and an alphabetized list of that person’s connections.  Click the “connect” link beside any of those and select from check boxes to identify yourself in any or all three ways:  business, friend or family contact.  Then you are one click away from sending the request to connect.

Plaxo offers a $59.95 upgrade to these functions.  This adds syncronization with Outlook calendars, a very handy de-duplication tool and the ability to send unlimited photo eCards.  You can sample the upgrades for 30 days.

New users may want to just try the free services for a while.  Import your contacts from Yahoo, GMail, Hotmail/MSN and LinkedIn.  Expand your network as you read the tweets and Facebook messages from all of those sources.  The only required investment is a little time.