Could this website (Mouth-Taped-Shut.com) be a secret production blog for David Fincher's The Girl With The Dragon Tattoo? /Film shared this story about it's possible validity. If you click the site it takes you to a Tumblr blog that includes some images and video taken on the set of the film. The images appear to hae been taken on closed sets, or in the editing room (as you can see the video below). The site has been online since August 20th 2011.
The site looks to be something that has been created unbeknownst to Sony Pictures, but I could be wrong. Take a look at the video and check out the site to see for yourself.