The IHC or the Institute for Human Continuity is as real as the characters in the new Roland Emmerich film, 2012.
Now whether or not you believe the world is going to end on December the 21st, 2012, this is just a movie. And the IHC is just a fictional organization from the movie.
Sony who distributes 2012, created a site for the Institute for Human Continuity as part of a viral marketing campaign for the film and it works great. It plays into the fears of many who don't know what to believe.
The site, is really detailed and has the feel of a real organization and it can be really scary when they play out the 2012 end of the world theories where celestial bodies crash into the earth. Makes you want to actually consider that the world may very well come to an end in 2012, which of course would make the movie all the more interesting.
Here's the trailer to the movie if you haven't seen it.