The poster is one of the oldest advertising media, and in an age of targeted internet campaigns and interactive pop-ups it would be understandable if film distributors had started to lose interest in paper and ink.

But this is not happening. Not only does the film poster remain an important release tool, but a new breed of posters is taking the form into the 21st century, incorporating visual and digital technology for that added wow factor.

One such development is the lenticular poster. These create the illusion of movement by applying images onto a plastic surface made up of parallel lines, each an optical lens, magnifying strips of image. Unlike holograms, lenticulars have shallow 3D depth and their motion is seen as a series of static images or 'flips' as the viewer moves past.

In the UK, Sony Pictures Releasing International (Spri) kicked off its campaign for the May 4 release of Spider-Man 3 by introducing 200 lenticular posters in theatres before Christmas. These show Spider-Man's costume changing from red/blue to black, in keeping with the film's plot. Sony also used lenticulars for its recent UK release of Ghost Rider.

Jane Robertson, Spri's senior advertising manager says lenticulars are most beneficial in cinemas, the first place many film-goers will see an image of the film. "We're getting lenticulars into cinemas way in advance of media hitting," she says. "It's much easier to sell films as moving images and if the public have already seen a lenticular in a cinema, hopefully it will be a trigger when press ads are released."

The UK's Momentum Pictures took the idea a step further this February and launched more advanced lenticulars for its campaign for The Illusionist, which allowed 28 frames of different images to be shown in succession, creating an animated illusion.

In the film's national 4,000-poster campaign, 100 sites used this dynamic image - 20 in London Underground stations and 80 on national roadsides. The poster features stars Edward Norton, Paul Giamatti and Jessica Biel - with Biel disappearing as the viewer passes.

The posters were created by the UK's Hyperspace, a department of outdoor marketing firm Posterscope, which has handled several innovative UK campaigns including one in 2005 for BVI which transformed 20 bus shelters into interactive film adverts showing clips from upcoming releases.

Price to pay

But these advanced methods come at a price. Hyperspace sells its dynamic imaging posters at $980 (£500) each, while Luminous Media - which manufactures its own electroluminescence outdoor posters - says standard lenticulars can range from $100-$685 (£50-£350) per ad.

Jamie Schwartz, theatrical marketing director at Momentum says the benefits of the posters boil down to the "talk-ability factor.

"These posters completely stand out and they work with the film," he says. "The illusion in the poster is so fitting to the film, and the fact people are commenting on them means we're having a much better response than a regular poster."

Film clients are usually early adopters of such technology, says Hyperspace project director Ben Milne. "We've found that film advertisers are some of the first to get on board with these new digital formats," he says. "They've got content that benefits the most from being able to move."

While lenticular posters give the illusion of a moving image, the industry is looking to create posters that can screen content.

Canadian imaging firm Xyz Rgb recently unveiled a poster that allows 8-10 seconds of video to be played. The technique, which effectively turns a poster into a screen, was demonstrated on a Terminator 2 poster. Director James Cameron was impressed, dubbing it the "holy grail of advertising".

It comes at a price, however: Xyz Rgb charges a hefty $200 per square foot for its video posters.

Other innovations include full-colour digital-ink displays - an invention by Israeli company Magink. Unlike a computer screen, the posters, made of tiny molecules of fat, can change colour instantly and remotely based on light reflection.