"No Strings Attached" Plot Summary: In this comedy, Emma (Natalie Portman) and Adam (Ashton Kutcher) are life-long friends who almost ruin everything by having sex one morning. In order to protect their friendship, they make a pact to keep their relationship strictly "no strings attached." "No strings" means no jealousy, no expectations, no fighting, no flowers, no baby voices. It means they can do whatever they want, whenever they want, in whatever public place they want, as long as they don't fall in love. The question becomes- who's going to fall first? And can their friendship survive?
"Friends with Benefits" Plot Summary: Dylan (Justin Timberlake) and Jamie (Mila Kunis) think it's going to be easy to add the simple act of sex to their friendship, despite what Hollywood romantic comedies would have them believe. They soon discover however that getting physical really does always lead to complications.
Update - July 1, 2011: It has been brought to our attention there is another film with a similar storyline. It's an independent film entitled, "Friends (with Benefits)", which premiered in 2009.