If you’d like to see the new features in action, head over to the Google Contacts page (or click the contacts link in your Gmail account). Note that so far the integrated Google+ contacts don’t appear to be available for Google Apps users.
The move is part of Google’s slow, but steady progress toward its goal of adding Google+ features to all its myriad services.
The new integration with the contacts list means that any Google Profile data your contacts have entered will now show up below any information you’ve added. Alex Chitu, writing at Google Operating System, notes that you can combine the two sets of data — what you’ve entered and what your contacts have entered — by clicking the “more” link on a contact page and selecting the “[Show external data] inline” option.
Chitu also reports that the Google Profile data is “automatically added when you enter an email address associated with a profile.” If you don’t want the added social data you can delete the corresponding email address and it will be removed.