Flock has recently release a update to their social browser which has features such as People in the Browser which allows you to reach to friends from multiple networks and stay connected to them all the time.
You can also now easily share photos and videos, text and your favorite links with other easily.
More than a year and half ago when Flock was first released I had written about using Firefox extensions in Flock Browser. Though the convertor does not work any more you can still access a list of around 1500 Firefox extensions that can be used in your Flock browser.
Well if you are not using Flock you should definitely give it a try and enjoy all the best resources for social networking from within your browser.