Note: Last week, Salesforce.com acquired Manymoon. Whether the buyout will lead to changes in Manymoon's services is still unclear.

While stand-alone productivity services are continuing to expand their connections to other Web tools, the role of larger social sites such as Facebook and LinkedIn in your productivity arsenal will likely grow. These mainstays of social interaction are rapidly becoming business hubs, too, for the simple reason that they make it easy for workers to connect with their colleagues.

In addition to Huddle and Manymoon, sports a plug-in for LinkedIn. Box.net and a growing selection of business tools can now connect to Facebook, too. Of course, these plug-ins are still in their infancy, and it'll be some time before the average worker heads to Facebook to manage a complex project.

If you're contemplating taking the plunge into the social productivity pool, here are three pieces of useful advice: