Screaming Sports (screamingsports.com) is lauching a social networking site which allows you to manage all of your fantasy teams, regardless of where they are hosted (Yahoo, ESPN, Fanball, etc.) in one interface.  It is not just meant to be a portal to your teams, but an actual management center with full ability to make roster changes and more.

In just a quick review, I was able to make all daily changes to my Yahoo teams with as much ease as at Yahoo itself.  I have not tested all of my own leagues yet, but for an initial launch it definitely has more than I would expect.  

Other features being promoted are:

• Automatic substitutions if your player gets an injury update
• Full news updates for all of your players
• Mobile access/ updates
• Your own sport homepage for blogs, team standings, updates and other personal customization
• An upcoming facebook application with similar functionality

  At this time all of the features are free.