I personally use Rapportive to learn more about the people behind the emails. However, some of you are might be more interested about the interactions that you’ve had with a person rather than the social networks on which they appear. Seeing and solving that lack of context, [Google has introduced a People Widget for Gmail(http://gmailblog.blogspot.com/2011/05/introducing-people-widget.html):
Email is just as much about the people you communicate with as it is what you communicate about. We think it can be helpful to view relevant information in context, which is why over the next two weeks we’re rolling out a new people widget located on the right hand side of your messages. The people widget surfaces content from friends, family and colleagues that is already available to you but may be hard to find and makes it easier to connect with them.
Next to every email message you can now see contextual information about the people in that conversation including recent emails you received from them, relevant Buzz posts, shared documents and calendar events. You also have quick access to a variety of ways to communicate with individuals, start a group chat or schedule a meeting with groups of people.