Whether a man and woman can have sex and stay "just friends" is cliched territory but this film is so much better than I ever thought it could be. It's not your typical romcom and it lacks that sugary coating that you usually get with this kind of film. It's a funny film yes, but in an indirect kind of way; you're getting the story and getting to know the characters and it just happens to be funny. It's not laughs just for the sake of laughs.
You'll have seen Ashton Kutcher in this kind of role before but you can't complain really - he does it so well. You get both the male and female perspective which makes the film all the more enjoyable. There is a bit of role-reversal too with Natalie Portman's character being portrayed as more 'the man' in the relationship and it is her idea to start the 'no strings attached' relationship. I can't understand people criticizing her though: yes she's a little uptight and she has her guard up when it comes to love but that's the point - her character HAS issues and the film is as much about her journey as it is about anything else.
The peripheral characters are a mixed bag (some of them are oddballs really!) and bring a bit of additional entertainment to the proceedings without being distracting from the main story. The whole film is really well put together - it's an 'observation' type of film and it manages to achieve a nice balance between romance, comedy and drama.
Overall, the film gets a thumbs up from me - it's a light-hearted, feel-good film that made me smile and giggle. There are a few extra bits provided on the DVD - the director's commentary is very easy listening. It's a shame there is no additional commentary with Ashton & Natalie and the 'alternate ending' referred to by the director is actually nowhere to be found in the bonus material. There are a few deleted scenes though and a nice featurette which includes the cast and crew and a bit more on the story of the film - pretty standard really but it's always nice to get some bonus material, than nothing at all.