Nearly a year ago Ancestry.com took the SSDI off the public airways in here and put it behind a paywall. You can no longer look up when Aunt Susan died, or any other relative, unless you belong to Ancestry.com and for a fee will be allowed to look up your ancestors.
This has left me and a lot of other people scrambling to find something reasonably equivalent. I have found a few that work, although not as cleanly or as efficiently as the original SSDI:
And lord alone knows how long ago Babelfish became a place you had to belong to to use, and now I see the future in 'upgrading' which always means pay more to get more.
Soon enough I suspect Google and/or Bing (which is what I use now) will start putting out watered down versions of their search engines, with the fancy high speed versions behind that paywall too.