WP Contact Manager

A great example of innovative work being done in the WordPress community is the WP Contact Manager by The Design Canopy:

WP Contact Manager is a different kind of theme for WordPress. With a little bit of work (outlined in detail below) it turns WordPress into a contact manager. You can add contacts through the regular admin interface, tag contacts, search them and more.

Very much in the early development stages, Joseph Scott points out that:

It’s a bit more involved to setup than Prologue, but it has the same basic premiss, use WordPress as the base and build features on top of it.

You can learn more and try out the demo here.