It's beginning to look like 2008 might be the year of the social aggregator as users begin to employ these emerging new tools to better manage and track their various online relationships, both personal and professional.  The introduction of these new Web applications, such as Friendfeed, Socialthing!, Spokeo, Second Brain, and Iminta, are making it easy for users to keep track of what their friends are doing online while simultaneously demonstrating that there are compelling alternatives to being social online without having to, say, actively maintain a Facebook account.  In fact, that's the very premise of this new type of social Web utility, which automatically tracks a user's public activity at sites around the Web including blogs, Flickr, Twitter, del.icio.us and so on, and creates a single convenient feed for others to consume and track.

I've been evaluating a number of these applications over the last few weeks and so far Friendfeed seems to be one of the best offerings in this space and also supports one of the widest array of online services, with Socialthing a close second.  Friendfeed currently monitors and aggregates one's social activity on 28 different services at the time of this writing, putting the result into one clean activity stream with a matching Atom feed.  While the latency on some of the services Friendfeed tracks isn't always great -- del.icio.us bookmarks seem to take a good long while to show up for example -- the integration ranges from the workable to the robust, with surprisingly good support for Twitter's hashtags for example.  Services you also might not have previously considered aggregating socially are also offered by Friendfeed including your Gmail status message, Netflix rental queue, and your LinkedIn activity.

However, a quick examination of Alexa traffic charts (partial sample below) shows there are no clear leaders in this emerging space that will soon be crowded with competition, if it isn't already.  Peter Cashmore at Mashable tracked at least 20 entries in this space mid-last year and so it's interesting to see how quickly Friendfeed has risen among the various players. Ease of use, visual elegance, and breadth of service tracking appears to be the competitive discriminator here, like it is with so many things in the Web 2.0 world. 

This morning Duncan Riley at TechCrunch covered the best ways to track Web 2.0 and he omitted social aggregators as something users should be taking advantage of, while explicitly including things like TechMeme and blog readers.  That's because social aggregators are far from being mainstream yet and the long term staying power of these individual Web applications aren't clear either, making it a challenge to decide where to "move in".  But increasingly -- as Robert Scoble did this week -- I'm finding that I'm checking my Friendfeed stream and not Facebook or Techmeme as much as I used to, and I suspect many others will as well as they find aggregated social activity streams the fullest and most convenient picture of their social network.  The egalitarian nature of social aggregators is also appealing at a time when many social networks are trying to put up as much of a walled garden as users will accept.

The wild cards for this space include major players such as Google or Facebook credibly adding social aggregation to their own offerings as well as a killer app mobile entry.  Open social networking standards such as Open Friend Format will also make this space interesting in the medium to long term.  Please tell us your favorite social aggregator below.