As others have said, there are a few funny moments and the film does start off well. However it does drag in the middle which had me wanting to fast forward, unfortunately though, I was actually seeing this in the cinema. The cameo which everyone goes on about, is funny but it stalls the film by lasting too long.
Unlike Shaun Of The Dead, I couldn't watch this film more than once and it certainly isn't on my list of DVD's to buy.