Community spirit – who’d have thought it? Aren’t we all meant to be isolated these days, what with our “atomised society”, our culture of e-mails and texts, and the lonely hours we spend behind computer screens, trawling the internet? And what about the busy Noughties lives we lead, ghettoised into enclaves of People Like Us, that have us rushing out of our houses, into our cars, in and out of shops? Even when we’re on holiday or sitting in bars, we’re not talking, we’re jabbing away on BlackBerrys. When did you last even notice the person sitting next to you on the train? Well, the chances are, not only did you notice them, you probably actually talked to them. Or maybe they bought you a cup of coffee, or started up a conversation by asking where you got your lovely shoes. Because neighbourly love is suddenly back.

Blame it on the floods, blame it on a concern for the environment we all share, blame it on a growing sense of uncertainty in the world, but suddenly Britain is blooming with self-motivated mentoring groups, local barter systems, swap shops, “save our shops” campaigns and neighbourhood “freecycle” networks that find new homes for old tat that would otherwise be destined for landfill sites. Even street parties are on the up: no longer are neighbours – with their loud kids/builders/sex – considered good moaning fodder.

And there’s a new social networking site to prove it. It was started by Danny Bull after a holiday in France, where “residents of the village that we were staying in, whom I’d never met before, gave me a gift for our newborn baby. I thought, ‘I wish the English were like that’ ”.

Then, when he moved to London, he was keen to meet his neighbours, but was, literally, afraid to ask. So he started www.myneighbourhoods.co.uk, and found that 60% of its traffic was purely social; only 20% of it involved searches for plumbers, builders or other local information. “People feel they can’t just go round and ask for help,” he says. “But they’re much more willing to reach out to others online. And this then facilitates interaction in real life.”

All we need these days, it seems, is an excuse. “Big dogs and young children – that’s what brings people together,” says Monica Hunt, founder of the Thurloe Square Garden Party, a neighbourhood bash that grows and grows each year. Indeed, walking the dog in Hyde Park was how her daughter Marina met her future husband, the television presenter Ben Fogle.

“All the dog-walkers know each other – it’s really sociable,” says Fogle, his black labrador, Inca, at his heels. His mother-in-law has roped him in to judge the kids’ cake competition. As he stops and chats to the residents, he says: “I’m definitely seeing a general longing to know your neighbours.”

But it’s not only dogs. New mothers often find that the talking point of a small baby is enough to break the ice on those lonely, mid-afternoon trudges around the park. The government’s Sure Start campaign has done much to bring local communities of mothers together, but it hasn’t stopped voluntary groups forming. One such example is in northwest London, where the Tufnell Park Parents Support Group – an entirely voluntary community of more than 250 local families – swap advice and neighbourly support through coffee mornings, parties and newsletters. “I met one of the organisers on the bus when she gave me a hand with my buggy,” says Stephanie Firth, a new mum. “She introduced me to the lady across the road, and then I met the woman who lives on the corner. It just blossomed from there.” Firth says she has gained valuable advice – and friends – from the organisation. “It really is a beautiful thing.”

And of course, there’s nothing like a crisis to get the Brits to pull together. The camaraderie among residents of Britain’s flood-ravaged towns has been compared to the blitz spirit, as neighbours, previously only on nodding terms, have put each other up, hosted impromptu barbecues to share defrosted meat spoils and found themselves chatting together after years of studied silence.

Clive Parkes, from Himbleton in Worcestershire, who was put up by a neighbour he knew “not that well”, says: “The whole village has become closer. I’ve met people I’ve never seen before in my life. Now that nobody is in their car, we’re getting to chat and share experiences. And walking down the street in my swimming trunks helps.”

Environmental concerns have also brought communities together. In more than 20 towns – including Totnes, Kinsale, Stroud and Glastonbury – residents are organising meetings to discuss how to turn their localities into “transition towns”, ones that are striving to “relocalise” food, energy, transport and local economies.

In March this year, Brixton became a transition town, and about 300 people have now signed up. Already in place is a communal allotment, regular workshops, talks and films (“which all end in the bar”); car pools are on the way. “We have to look at the benefits of being reconnected,” says the Brixton group’s founder, the actor/ director Duncan Law. “In a period of disturbance, it’s essential to have a community where people borrow sugar and know each other’s names – we all have resources that others need.” Although all the members joined out of concern for the climate, they have discovered that green credentials are not the only advantage. “You benefit right from the first meeting, when you meet like-minded people,” Law says. “It’s why the model is so powerful. I’ve made many friends – it can take me 20 minutes to get to the bus stop now.”

If getting in with your entire town seems a bit deepend, why not start small? The mentoring movement in Britain is seeing a lot of love right now. Why? “The beauty of mentoring is that it’s not a one-way street,” says Steve Leach, of the cabinet-funded Mentoring and Befriending Foundation. “I mentor a 26-year-old man with learning difficulties. I know that if I support people to take part in society, it improves society for me. It’s not just altruism – it’s better for everyone.”

Social capital – it’s what we’re all after these days. As the inveterate mentor Baroness Julia Neuberger says: “It’s instinctive. It’s like, ‘Gosh, I don’t know the people next door.’ I love it. Everybody feels better for doing it. Everyone gets a buzz from it.”

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