We are interested in something similar.  It is a bit challenging without having customizable fields for contacts where you could name them as needed and then report and filter upon the fields too.    In the interim, one option is to create a Contact Type called “New Leads”. Then a Karbon Administrator can export the All Contacts report (In Contact, cloud with down arrow in right corner of screen).  This downloads an Excel file where you can sort by Contact Type and see the “new leads” in your contact database.