I've watched this trailer before the Transformers movie, and it's one of the coolest things I've seen lately. There is no movie title, no clue what the movie is about whatsoever, and it's entirely shot with a handheld camera. You can only see at the end that is from producer J.J. Abrams (Lost, Alias) and it comes to theaters on 01-18-08.

If you search on the Internet there is no too much info, which means that they are keeping the secret very well. I've read that they posted the video on YouTube but it was quickly removed (although you may find some poorly shot clips taken from inside a movie theater).

The plot line according to IMDb is: "Revolves around a monster attack in New York as told from the point of view of a small group of people".

I would recommend you to watch the official trailer here at Apple.

They refer to the movie as "secret J.J. Abrams project" or by the code name "Cloverfield"...very mysterious...

This is the only official web site in this one, you may find some others websites posted on blogs, but J. J. Abrams himself confirmed that the other web sites that people have found are not related to the movie.