Rapportive is a free browser add-on developed for Firefox, Chrome and Safari that allows you to view your contacts' social media profiles and activity right inside Gmail. The add-on works with both Gmail and Google Apps. Give it a try! It's quick and easy to set up and it truly enhances your traditional mail client.
There are a handful of popular social CRM (customer relationship management) tools available that integrate with your mail client.
Last month, RIM (Research in Motion) announced the acquisition of Gist, one of the more widely used applications that enhance email contacts by displaying profiles that includes blogs, so