iPhone O.S 4 includes linked contacts

Apple iPhone operating system version 4.0 offers its user with new add on which is linked contacts. It appears at the below of each contact info layout.

Once a linked contact has been added to a primary contact, the info pane for the primary contact merges that contact information for both contacts into a single pane relabeled as "Unified Info." An option at the base of the unified pane lists the number of linked contacts and directs users to a "Linked Contacts" pane to merge even more contacts into the unified list.

Read more at appleinsider