Derek Davis
The full Irish
Broadcaster Derek Davis is passionate about his food. A keen cook, he is horrified by what is currently being offered by hostelries around the country as the 'full Irish breakfast'. Speaking at a food tourism seminar last year, he said many tourists gag when they taste this meal, that Ireland produces what are arguably the worst rashers and sausages in the word and that we're in denial about how appalling the traditional breakfast can be. His particular bugbear is the deep-fried sausages and the fried eggs "which are started at 6am and kept alive in lukewarm fat".

Bill Bryson Litter The ursine Iowan travel writer Bill Bryson has a bee in his bonnet about litter. "I've said on a book tour last year that we need to do something about litter in [the UK], " says Bryson, who now lives in Norfolk. "I assembled a small army of willing people, who all want to help in some way, but I didn't know what to do with them.

I've never run a campaign." Luckily for Bryson, the Campaign to Protect Rural England was happy to help him. They also made him president. Now, the American is not just a litter vigilante but a champion of the British countryside. "There's an obvious irony in an American lecturing the British on their landscape, or, indeed, any aspect of British life, " says Bryson. "But I've known Britain for 35 years."

Gloria Hunniford
Daily exercise
In 2001, Gloria Hunniford's husband Stephen had a heart attack. He survived, but the surgeon said he and his wife needed to change their eating and exercise habits dramatically if they wished to have an old age. Not only did they change but Hunniford started a campaign to encourage people to exercise for 30 minutes a day through the British Heart Foundation. Given her gluttonous Irish upbringing, it was something of a struggle.

"My mother was always making cakes and buns, " recalled Hunniford. "We used to eat five meals a day: breakfast . . . which was always a fry-up . . . lunch, afternoon tea, dinner and supper."

Joanna Lumley
Hedgehogs
The actress is perhaps the most prominent of a host of celebrities who have implored Scottish Natural Heritage to save the hedgehogs on the Hebridean island of Uist. Scientists found the hedgehogs were eating the eggs of the rare native wader birds and 690 of the spiky beasts have been killed in culls . . . by lethal injection . . . since 2003. But the celebrity endorsements have worked. A proposed cull scheduled to start in March this year was called off. The rest of the island's hedgehogs have been moved off death row and will now be transferred to sites on the mainland.

Roy Keane
Guide dogs
The Sunderland manager is a patron of the Irish Guidedogs for the Blind Association and has lent his support to its various causes over the last few years. The charity is dedicated to providing mobility training and aftercare services to visually impaired and blind people, free of charge. "I am a great admirer of their work and the dedication of the staff and volunteers, " Keane says. "The impact that a guide dog or an assistance dog has on the individual and their family is amazing." A keen dog lover, he's often seen out and about with his own golden Labrador, Trigs.

Heather Mills McCartney
Avoiding milk
Heather Mills McCartney has lent her considerable celebrity heft to such worthy causes as banning landmines and fur. But her campaign last year was against an altogether humbler enemy . . . milk. She claims that her recovery from a post-amputation infection was down to her dairy-free vegan diet. Last year she went public with a controversial theory that dairy products can cause cancer. Several experts poured scorn on this, including Dr Lesley Walker, of Cancer Research UK, who said tests to assess the cancer risk had been inconclusive. Mills McCartney, though, stands by her position.

Helen Mirren
Energy saving for the old
Helen Mirren, whose protean talents have seen her tackle roles as disparate as Queen Elizabeth I and Queen Elizabeth II, wants the government to do more for pensioners in cold weather. She has backed a campaign by the National Energy Action charity to promote energy efficiency in the significant portion of pensioner homes that spend more than 10% of their income on fuel.

"The charity tirelessly campaigns to make warm homes affordable for people . . . particularly the elderly and vulnerable, " says Mirren. The Queen would, no doubt, be delighted at Mirren's concern for her ageing subjects.

Sheryl Crow
Loo paper
She's got some cheek, that Sheryl Crow. The American singer has said that, to save the planet, we should all use "only one square per restroom visit. . .except on those pesky occasions where two or three can be required". Crow's suggestion raises many questions. Is she talking only of number ones? Do men acquire credits for their paperfree standing-up visits that can be used for more serious assignments? Crow has not elaborated.

Jeanette Winterson
Trees for cities
Author Jeanette Winterson likes trees a great deal. She has, she says, planted hundreds in her Gloucestershire home and, in the past few years, has done the same in London, as well as supporting the charity Trees for Cities. Why? "Most people live in cities, " she wrote when she joined Trees for Cities in 2000. "This will not change, whatever John Prescott does to the countryside. City parks and planted squares are small pauses in the breathless narrative of traffic and work. We need those pauses. Our bodies benefit from the filtered air the trees provide and from the natural sound barrier any planting creates."

Angus Deayton
Tennis for free
Angus Deayton has weighed in on one of the great issues of our time . . . free council tennis courts. Joining his comedian friend Tony Hawks' Tennis for Free campaign, he has encouraged local councils in Britain to offer their courts for free, either in off-peak hours or permanently. "At the moment, " said Deayton in 2003, "we are low on the tennis resources front in terms of Wimbledon champions, especially on the girls' side, so if we are looking to rekindle an interest in the sport it would be a good initiative to introduce." It was not quite 'I have a dream' but Deayton's intervention seems to have been a success. Many councils now offer courts for free.

So Solid Harvey
Reading books
When Passionet, a "multicultural" bookshop, launched a reading campaign aimed at children, their managing director Natalie Smith said she wanted "to put the bling back into reading". Harvey, from the nowdefunct grime collective So Solid Crew, was, then, a natural frontman. As an ambassador for Star Reads, Harvey has been vocal in his opinions about the school curriculum.

"Schools force too much on kids, " he said. "It makes reading very uncomfortable."

Ambassadors are encouraged to suggest texts. Harvey chose Boyz to Men by Yinka Adebayo and World Team by Tim Vyner, with the advice: "Reading is knowledge.

And knowledge is power."