The American Red Cross (ARC) has set up a website in response to the Tennessee tornadoes. I learned this because I follow @Redcross on Twitter as you should.
This site is for public information about the American Red Cross response to the Tennessee tornadoes of February 2008. [Source, Tennessee Tornadoes, American Red Cross] [more info]
They had a similar site for Northwest Flooding 2007. If you are looking for loved ones or have been displaced by a disaster, please use the Safe and Well List to help inform family and friends. Safe and Well is easily accessible through your phone using Twitter.