The official site has a large amount of information about the movie and cast. However, I wish to emphasize the production notes and Matthew's bio a little bit more.
The production notes includes an interview with Matthew. He sounds as if he enjoyed the filming. Also see the glowing biography of Matthew
Thanks to SecretWifeofTomQuinn, she noticed that the official website for Death at a Funeral has new images and music, although the trailer is the same. Go have a look!