The Company Directory lets you see all your contacts and their presence. To open all the details, click on the name of the contact.
Your Favourite list is displayed by default, so if you want to find another person, just start entering their first name, last name, department, a custom field (like department), or a combination of any of these. The Directory also makes provision for VIP contacts, which will appear under Favourites, which you can add specific call routing rules for. You can add specific call routing rules for Blocked contacts too.