Smartr Inbox for Gmail installs as an add-in to , , or , and once installed launches automatically when you run Gmail. When you first run it, it indexes your contacts, which only takes a few minutes, even if you have 1,500 or so of them. Then you fill out forms to link it to Facebook, Twitter, and LinkedIn. At that point, it links your Gmail account to those social networking sites, imports their contacts, and indexes them. That only takes a few minutes as well.
Once all that is done, Smartr Inbox for Gmail can show off its stuff. It runs as a sidebar on the right-hand side of Gmail and performs several useful functions. First is that when you are reading an email from someone, it shows information about that person from Facebook, LinkedIn and Twitter, including recent tweets and updates, contact information, and so on. You can also see a history of your email communications with the person, any contacts you have in common with the person, and a graph highlighting data about your communications with them, graphing the number of emails sent between the two of you over a year.
There's much more as well. If you're just looking at the Inbox itself, and not reading an individual message, you get an overview of all of the tweets and updates from all of your contacts on Facebook, Twitter, and LinkedIn. In addition, you can post to Facebook or Twitter as well. And you can search through all of your contacts from all services as well.
Smartr Inbox for Gmail would be even more useful if it included integration with the Google+ social networking service, and instant messaging services such as Google Talk. Still that's a minor quibble. Anyone who uses Gmail and Facebook, LinkedIn, and Twitter would do well to download and install it. If you have an Android phone and like Smartr Inbox for Gmail's contact management, you might be interested in the free mobile app , which uses a similar format.
Note that Smartr Inbox for Gmail comes from the same folks who make the add-in for Outlook, and it performs similar functions to that tool. So if you have Outlook and like what Smartr Inbox for Gmail does for Gmail, you might want to give the Outlook add-in a try.