Plaxo started with an offering to keep your address book up-to-date. Today, they securely host address books for more than 40 million people (and growing).  More recently, they’ve helped bring those address books to life with "Pulse," a different approach to social networking:  it is not a place to see how many online "friends" you can collect. It’s meant to be a better way for you to stay in touch with the people you actually know and care about. It’s a dashboard for seeing what the people you know are creating and sharing all over the open web. You can hook your Pulse account up to all the places where you create or share stuff (your blog, Flickr, Twitter, Yelp, and more than 30 other sites).