Mediocre? Did we watch the same film? It's superb. One of the finest horror films of the 21st Century, with incisive commentary on Bush's America in miniature (ie the events in the shop, with the rise of religious fanaticism, the soldiers being "sacrificed", etc) and a brilliant comment on gun control (if only they'd left the gun behind in that final moment). The ending is astonishingly bleak, brilliant, and unforgettable. And you watched this whilst proofreading your thesis? That just makes me go hot and cold all over. It's almost as bad as learning someone watched Lawrence of Arabia for the first time on a mobile phone. Shudder...