The campaign is one of the first applications of near field communication (NFC) technology. A pre-programmed chip on the back of the poster triggers an NFC-enabled mobile phone to visit a mobile website.
The phone's 3G connection loads the website and streams the minute-long 'X-Men First Class' trailer, hosted on YouTube.
Five JCDecaux six-sheets around Holborn, including two sites on Tottenham Court Road, have been equipped with an NFC chip in a bid by the technology provider, Proxama, to demonstrate the technology to media agencies.
Outdoor media specialist Posterscope is using the technology as part of its work for 'X-Men First Class' distributor 20th Century Fox.
The technology is expected to feature in several makes of mobile phones due for release, although few models are currently available.
They include the Nokia C7 and the Google Nexus S.
Proxama, which is helping Nokia sell NFC solutions to the marketing industry, has distributed a number of handsets to media agencies.
James Davies, director at Posterscope's innovation and digital division, said: "What is so exciting about this layer of interactivity is its simplicity and the size of the opportunity for generating scale.
"There are 130,000 commercially available poster sites in the UK that can be instantly enabled. For the client the cost of each NFC chip is extremely low and the consumer receives instant fulfilment."
Proxama is able to report data on the how many mobiles have gone onto the website, which poster location has triggered their visit and how many have started playing the video.