I Am Number Four based on the book by Pittacus Lore. This interesting name is the pseudonym of James Frey, a very controversial author of the adult market. From what I've read about him, it was a smart idea to give him a pen name for his entrance into the YA genre (some parents may have been unhappy if they saw his name on a book their child was reading). I'll let you discover why (it begins with A Million Little Pieces but does not end there).
The movie was good, featuring lots of sci-fi action and special effects with a budding romance thrown into the mix.
The main character is one of nine alien children who were sent to earth, each with a guardian, when their home planet, Lorien, was decimated by the bad guys, the Mogadorians and their huge, mutant, naked flying squirells (okay, that's just what I think they look like). Whew. Now they are teenagers who move from place to place in hopes that the pursueing Mogadorians don't track them down and kill them.
Alex Pettyfer who plays the main character, Number Four, also happens to be the main character in the movie Beastly, which is based on the book by Alex Flinn and which is also currently in theaters (this guy is really getting around the YA book scene! In 2006 he was the lead in Alex Rider: Operation Stormbreaker based on the Alex Rider Series by Anthony Horowitz. He is also rumored to be in the upcoming films, The Mortal Instruments based on the book series of the same name by Cassandra Clare and The Seventh Son [perhaps not a YA movie though] based on the YA book, The Young Apprentice or Spook's Apprentice by Joseph Delaney. Wow!).
So back to the book. I have only read the first few chapters (thank you Amazon "sample" feature for Kindle books) which actually read like a movie. The book of course predates the movie, but the way it is written makes it easy for the reader to visualize what is happening and one could easily imagine it being a movie (which it is). But as is inevitable, the story has been changed in the movie though from what I can tell, still gets all of the important elements across and sets up for the sequel at the end. I Am Number Four is the first in the proposed seven book Lorien Legacies Series. Book two, The Power of Six, which is from the perspective of Number Seven, has a release date of August 23, 2011. So probably a sequel movie will come out at some point because of the hugely incomplete storyline and also because I Am Number Four has done pretty well at the box office.