The Xobni Outlook add-on is at its heart a tool to search for and find e-mail and contacts faster. As an interesting, but far less crucial, secondary function, Xobni also collects statistics, like the frequency you e-mail a contact and at which hour, that can eventually help you manage your social relationships.
Visually, Xobni displays as an attractive sidebar that slides in an out from the right and over the reading pane. It features a Xobni search bar, faster-acting than Outlook's own by miles, and a Google search bar for more general queries. The search results pull up people, messages, and the subject of e-mail attachments. You'll be able to interact with the profile, message, or files from there. When at rest, Xobni displays the profile it's collected on the contact--from a hyperlinked e-mail address and phone number to a Skype plug-in, Facebook picture, and LinkedIn profile, assuming the contact has enabled third-party sharing in his social network settings. You'll likewise be able to get at the contact's network, past conversations, and files from here.
Activate the premium version, Xobni Plus, for $30 (and a free, 14-day trial) and you'll open the door to broader search data (appointments and tasks), more powerful search terms (phrases and Boolean), and an advanced search builder. Xobni Plus also includes full text and direct e-mail filters. Best yet, Xobni Plus adds its index of e-mail addresses to the "To" field of every message you compose, sometimes replicating, but nevertheless vastly expanding, your address book.
Unlike many other Outlook add-ons, both free and upgraded versions of Xobni add functionality without greatly dragging down Outlook's performance. The interface doesn't get in the way, and, in fact, makes communication easier.