Ok, I might be late!
I just noticed today the Gmail’s brand-new People Widget and found it really useful!
You can communicate with individual contacts easily through the people widget, or just use it to find basic information. Simply click on the contact’s name on the right side. From there, you’ll see:
Information about your contact, which may include information such as their email address or occupation. This information comes from your account’s Contact Manager Recent buzzes your contact has posted that are visible to you Recent email your contact sent you Google Calendar events if your contact’s Calendar is shared with you Google documents shared with both you and the contact
Check here for more info about the People Widget