Another teaser that is worth a catch is the Wars of the World teaser. The story is based on the same name novel written by H.G. Well, the man who also wrote Time Machine. It's quite interesting that while this story is turn into radio broadcast many years ago. As the story telling is so real, some people even believed that alien is comming to attack!
This time the movie is made by Speilberg and Cruise. Sounds promising..
Related Link: War of the Worlds Teaser Trailer