In an industry where only the select few can afford to snap up the rights to the latest bestseller-to-be at galley stage or bid for the hottest spec screenplay doing the rounds, producers need to be shrewder, quicker off the mark and more esoteric in their thinking when they are seeking out compelling stories that can be turned into marketable films. Life stories, documentaries, radio programmes, magazine and newspaper features, blogs, and even TV ads are all rich territory for canny producers mining for material.

'We're a small company, so we can't put our hands in our pockets and buy expensive book options,' says Suzanne Mackie, director of development at the production outfit Harbour Pictures, who produced Calendar Girls and Kinky Boots for Buena Vista. 'So we keep our eyes and ears close to the ground for those nuggets that seem to come out of British and American life. I get a lot from radio. Our latest film, Map Of The Universe, came from listening to a late-night science programme.'

Little Bird's Jonathan Cavendish has, with his US producing partners Mark and Adam Kassen, optioned the rights to the UK documentary Blue Blood, about the Oxford University varsity boxing team and their annual rivalry with Cambridge. 'As a company, we've made quite a few documentaries,' says Cavendish, 'but I've never optioned one before. One of the great advantages in terms of funding the development or even the production is that, in our business, it's a lot easier to get someone to look at a 90-minute documentary than read a 300-page book.'

Producer Michael Kuhn went along to the screening of the graduation films at Britain's National Film and Television School and had his company Qwerty Films purchase the film rights to a 20-minute documentary about a UK mini-golf team travelling to the world championships in Romania. Meanwhile, Jon Ronson, a columnist for the UK's Guardian newspaper, has sold the option to turn his Out Of The Ordinary column into a film to producers Graham Broadbent and Peter Czernin at Blueprint Pictures. Borat writer Dan Mazer is adapting Ronson's quirky observations about his life and family, with Film4, Pathe and the UK Film Council co-producing.

From the pages of a magazine

In the past decade, on the back of magazine-born successes such as The Insider and Adaptation, trawling publications for film ideas has become a common activity for producers, spawning a late-1990s flurry where high-profile publications retained agents to facilitate dealings between themselves and the industry. Most big-name journalists also have agents to secure deals when a producer comes calling. This year alone, Paul Haggis' In the Valley Of Elah was based on Mark Boal's Playboy magazine piece Death And Dishonor; Die Hard 4.0 was inspired by John Carlin's 1997 Wired magazine article about cyber-terrorism, A Farewell To Arms; and Universal purchased the rights to Warren St John's New York Times feature about a refugee football team in Georgia called The Fugees for a breathtaking $2m (including rights to St John's spin-off book).

Meanwhile, George Clooney is collaborating on a screenplay with writing partner Grant Heslov under their new Warner Bros-based production banner Smoke House called Escape From Tehran, based on another Wired magazine piece about how the CIA smuggled six Americans out of Tehran during the 1979 hostage crisis under cover of a fake sci-fi movie.

My life in your hands

When Universal recently announced it was putting forward American Gangster screenwriter Steve Zaillian for the best original screenplay Oscar, the studio created a minor storm due to the fact that Ridley Scott's film is notionally based on Mark Jacobson's 2001 New York magazine article, The Return Of Superfly. 'The writing credit determination on American Gangster was made by the Writers Guild of America, who ruled that Steven Zaillian's screenplay qualifies as an original work; Universal is following their direction,' says a Universal spokesman. 'Jacobson's article was used as research material but the film depicts a much more expansive portrait not only of Frank Lucas but of the period.'

The question for some producers is whether they need to purchase the rights to a feature in the press rather than just go straight to the story's subject for their life rights.

'You could do that although for chain of title, it's good to have something to hang it on,' argues Rhodri Thomas, vice-president of development and production at The Weinstein Company. 'Even if an item is in the public domain, I'll still go to the people who created the item. If you get the definitive piece, it's a good way of preventing anybody else from doing the story.'

Buying the book or magazine article also assumes that version of the story can legitimately be adapted for the screen.

Although they often get turned into books before producers come sniffing, personal blogs are also beginning to offer lush pickings for producers. Diablo Cody, whose debut screenplay for Jason Reitman's teen-pregnancy comedy Juno is generating Oscar buzz for Fox Searchlight, was cold-called by producer Mason Novick after he read Pussy Ranch, her frank, funny blog about the local sex industry in Minneapolis-St Paul. 'Every day for six months I read her blog and it made me laugh,' says Novick.

And when an unemployed Canadian named Kyle MacDonald wrote a blog called One Red Paperclip, tracing his astonishingly successful eBay efforts to swap his way up from said office item to a two-bedroom farmhouse in Saskatchewan, Walter Parkes and Laurie MacDonald sat up and took notice; Kyle's story is now in development at DreamWorks.

Getting rights to someone's story, however, is more often than not a painfully protracted process, as Mackie and her Harbour Pictures partner Nick Barton discovered on Calendar Girls, about the Women's Institute group who posed nude for charity: 'I heard about the story and managed to track them down off the internet,' says Mackie, who got in there before other interested parties including Scott Rudin and UK comedienne Victoria Wood showed up on the scene. Even then, gaining the trust of the women and their families was a tough process.

'It is someone's life and it's easy to muck around with,' says Mackie, who had Buena Vista UK on board. 'You give them consultation rights; what you don't give them is approval. If we gave anyone approval, we'd never move past the first hurdle. No studio backing a film would want the source material if that were the case.'

Consultation rights are usually built in to the life-option contract, 'which is complicated as hell to negotiate,' says Mackie. 'That took over a year to sort out on Calendar Girls.'

The life option typically grants the rights for the film to be shown in perpetuity, as well as granting producers the rights to any ancillary spin-offs that might result, including theme park, TV, stage and book rights.

'The worst thing about life stories is that within a few months of saying yes, they get confronted with this massive legal document which is so onerous, it looks like you're selling your entire life for a measly whatever it is,' says Mackie.

Life stories rarely go for the big dollar signs that often flash up in people's eyes, unless, of course, it were someone like Formula One driver Lewis Hamilton or the parents of the missing child Madeleine McCann, Kate and Gerry.

Mackie always warns her subjects that narrative films never adhere in documentary fashion to reality. In Kinky Boots, which Harbour sourced from a BBC documentary about a factory owner who hired a drag queen to rescue his ailing shoe factory, Mackie and Barton decided to open the movie with the death of the owner's father to enhance his emotional arc - even though said parent was very much alive and kicking. 'That was horrid,' says Mackie about sitting down with father and son to explain their creative decision. 'And if they had said, 'Absolutely not,' we wouldn't have done it.'

A producer's nightmare is their subject withdrawing their support, although contracts are usually so watertight that participants can be injuncted from berating the film publicly; but it can still result in unwanted headlines.

The search for new sources

Some producers look even further afield. Working Title spun the secret agent character Rowan Atkinson played in a long-running BarclayCard TV ad campaign into Johnny English. And TWC's Rhodri Thomas once mulled over the idea of developing an innovative deodorant commercial into a film. 'It's the reason why people adapt video games,' says Thomas. 'It's not necessarily just a great story you're looking for, it's also an interesting world in which to set the story. Often a commercial can create a fascinating, high-concept environment that you can then build characters around.'

From TV ad-land, it is only one small step to basing an entire film around a product, and a sex-toy at that, as screenwriter-producer Stephen Raphael did with his 2006 mockumentary Rabbit Proof about the rabbit craze sweeping the globe. Although sex-aid companies like Ann Summers have trademarked versions of the rabbit, Raphael discovered the vibrator originated in Japan before the rest of the world caught on. 'People were flagging up copyright issues, but in fact it's a generic term,' says Raphael. 'We went around to a load of different companies that make these vibrators and cleared rights with all of them. They were all more than happy to have their wares advertised.'