Google is continuously adding social features to its products for the last year or so, recently added features to integrate Google+ and Gmail. Today Google announced that contacts have been added to the Gmail search bar, now if you search for contacts in Gmail search they will reveal more information about your contacts.
This feature may not be great but it makes it easy to get contact information of your contacts with search. The search result brings up the contact email address, associated profile photo, links for a quick chat, video chat and of course the recent conversations with them.
It also shows on which circle they are in your Google+, if they are not in your circles you can add them right away. This is all done in a snap and it is really quite useful. You can always get this information from contacts, but you have to go contacts and search, this way the information is right there just a click away.
If your contacts have a Google+ profile, the information will be kept upto date, meaning if they change their profile info, it will reflect immediately in your Gmail contacts info.
Apart from the search improvements Google also improved circle integration and search according to Google blog post. When you select a circle now you will profile photos of people who are in that circle, if you click on them you will taken directly to their search result with contact details page.
Now you can use search filters for searching circles. For example find messages from specific circle by typing circle:[circle name] in the search box.
Source: Gmail Blog
