Allow users to connect with their friends and aggregate in other signals, such as flickr feed, tweets, and beyond.

threadsy is the first truly integrated communications client. see your email, social networks, and twitter in one place.

Friendfeeed was the early forerunner in this space. They aggregate streams from a variety of sources (including straight RSS feeds) and allow for users to organize and derive signal.

Pulls in many social network streams including Twitter, Facebook, LinkedIn, and Foursquare. Silverlight based and available for Mac and Windows platforms.

A personal news aggregator that makes a sorted list of important tweets and other social signals like Digg, delicious and photos into your Feedera inbox.

Pulls in tweet stream, blog posts, Amazon reviews, and a variety of other data sources to generate signal

Windows Live (including hotmail) offers features that let you know “What’s new with your network”, while they don’t make it easy to add in social signals from other locations, this could be accomplished with partners like Gigya* or Janrain.

All your social updates in one place. Clients available on Mac + PC, Android and iPhone platforms.