Watching Free Run, a blurry, vertiginous MTV-style short by London-based photographer Henry Reichhold, is getting the digital equivalent of a sugar rush. Just 76 seconds long, the stylised film shows a young runner vaulting over commuters, shoppers and tall buildings in London, set to a Vangelis-like score. Free Run was shot on a camera-equipped mobile phone, as were about 150 other works screened recently at Japan's first Pocket Films Festival in Yokohama. Its brevity can't compare with the shortest film, which clocked a giddy 12 seconds, but visitors with time and patience could watch full-length features filmed with the gadgets. France, possibly the world leader in the new field of pocket movies, supplied several productions that stretched to a full 90 minutes. The idea of shooting, editing and even screening movies on mobile phones may seem odd, but its proponents take it very seriously, citing its potential for free, intimate creativity. Reichhold praises the 'rawness and vitality' of the medium and calls the cellphone software now available 'revolutionary'. 'This has enabled people to control every aspect of the creative process, from editing to adding a soundtrack and text - and in many cases all this can be done just using the phone,' he says. That rough edge and a fair share of indulgence were on display at the festival, which showcased 48 clips selected from 400 submissions from Japan. Some were produced literally on the run by people clutching phones as they whizzed through traffic or - as in the nine-minute Walkers - sped around Japan on a bullet train; others were made by amateurs who should probably get out of their bedrooms more. But the best, such as Passerby, a witty experimental collage by Michiko Tsuda, overcome their grainy technical limits with a quirky inventiveness. The split-screen entry shows a couple filming themselves entering a washroom then meeting in the corridor and exchanging mobile phones. 'The quality isn't great but the phones are really portable and you can shoot something immediately so it feels very fresh,' says Tsuda, a 27-year-old digital design student. 'And because shooting is so fast, lots of other ideas come out in the creative process.' Daisuke Kobayashi, a 25-year-old video production assistant, won the top jury prize and 500,000 yen (HK$35,700) for his first effort in the genre - 720/24, a three-minute compendium of ordinary scenes shot at angles reflecting the time of day around Tokyo during a 24-hour period. 'I divided up the day into angles for shooting,' he says, explaining his approach. 'At noon I stood the phone up straight and filmed, then shot from different angles depending on where the sun was.' Buoyed by his successful effort, Kobayashi plans to invest some of his prize money in similar projects. 'For movies with a scenario and a main character, video is probably better but the distinctive feature of using a cellphone is that it very direct and you can film events as they are happening,' he says. 'Most of my friends have never thought of using a mobile phone in this way but I think the festival will help change that.' Given the expanding technological capabilities of the once humble handset and its ubiquity in Japan (the number of subscribers recently passed 100 million) it was only a matter of time before their owners began making movies, say the Yokohama festival organisers. Mobile phones are already widely used in Japan to surf the internet, shop, read novels and shoot short clips of family events. Newer models include so-called 1-Seg technology, which allows users to watch crystal-clear digital TV broadcasts. But a judge at the festival, Masaki Fujihata, concedes that despite its potential, the medium is still in its infancy in Japan. 'The idea of a pocket festival began in France three years ago, so we're behind,' says Fujihata, who teaches film at the Tokyo National University of Fine Arts and Music. 'There are a lot more phones here but I think many Japanese have a harder time thinking of them as creative tools.' He suggests a greater appreciation of film as an art form accounts for the faster development of mobile-phone movies in France, which coined the term vlog - a contraction of blog and video. Even so, its promise in Japan, which claims to post 38 per cent of the world's blog pages, is enormous, says Fujihata. 'Next year we're confident there will be a lot more movies, so my job will be harder.' So far, the audience for these movies seems divided into two categories: tech enthusiasts and artists who perceive a nascent creative revolution, and ordinary punters who can't get past the grainy quality and sometimes abstract themes. The quality problems are most obvious when the pocket movies are shown on a full-sized screen, like one basketball game enthusiastically if inexpertly filmed by Tokyo primary school students. 'I have to admit was a bit bored,' says office worker Keigo Arakawa, who claims to have attended most screenings at the festival. 'I can understand making the movies, because that's fun, but not watching them.' But others, such as Hiroko Sakuta, a 28-year-old digital design student at Tama University, are inspired. 'The attraction is that because they're so short and small the directors have to really focus on winning our attention. They wouldn't look good up on a big screen but because they're small, you don't mind the lack of quality.' Fans point out that portability of the mobile phone has already made it one of the most important and democratic technologies of the new century. It has been used to record some of the decade's most momentous events, including the recent assassination of Benazir Bhutto and the gruesome execution of Saddam Hussein last year. More experienced users such as Reichhold say the spread of new software and editing techniques, and faster shooting and transmission speeds will revolutionise what has largely been an amateur's medium. 'One can presume that the next generation of video-enabled phones will compete with camcorders,' he says. Easy dissemination on the Net adds to the medium's appeal. 'The potentially huge audience it can draw has taken filming out of the living room and into a host of new sharing platforms,' says Reichhold. 'From the diary-type sites such as Facebook to self-publishing ones like YouTube and MySpace, the ability to distribute the material is out there.'