Smartr is a powerful free extension for Google Chrome. It adds a sidebar to Gmail (this is where having a big screen is useful in keeping clutter at bay). The sidebar houses an enhanced contacts manager. When installed, Smartr goes through your contacts and gives you the option of adding your Facebook and Twitter accounts. When you click into an email or start to compose a new email, Smartr calls up everything it knows about the person who sent it or the person you are about to send it to, including recent tweets and facebook updates, photographs and other information. It also gives you a history of your email contact with that person and identifies other people you often email in association with them. Smartr surfaces quite a bit of information from within and outside Gmail in a very effective fashion, and could be very handy for businesses trying to leverage their existing contact lists.