Reviews for the "Diary of a Wimpy Kid" movie are available on Metacritic.com and RottenTomatoes.com. Both sites allow professional critics and regular users to submit reviews of movies.
Metacritic.com brings together reviews from other sources to create a single resource for finding reviews. It then combines the ratings of all of the reviews to get an overall average for the film. The site also has trailers and other details about the movie.
RottenTomatoes.com is similar, hosting professional and casual reviews while averaging the ratings out for an overall review. The site also has a forum where users can discuss the film and reviews.