Cairo, it wasn't. But at about a quarter to four last Saturday afternoon, on a crowded backstreet in central London, something happened outside the Egyptian embassy that deserves at least a footnote in the annals of protest history. A crowd of students weren't kettled.

In the context of recent British protests, this was a near-miracle. At each of the previous four major student protests in London since the Millbank riot on 10 November, police have kettled – or, in their terminology, "contained" – thousands of protesters, preventing them from leaving an area for several hours, and often from accessing basic amenities such as food, water and toilets.

Police kettle protesters supposedly to quell violence, but protesters arguably only turn to violence out of frustration at being kettled. Most notoriously, police trapped hundreds of teenage schoolchildren inside a tight grid on Whitehall on 24 November – and only subsequently did a few of them smash up a police van abandoned in their midst.

Saturday's non-kettle, then, was a victory in itself. But the real excitement wasn't that it didn't happen – but how it didn't happen. It is difficult to pinpoint exactly why police and protesters behave in a certain way at a certain time, but one explanation for the kettle's failure to form lies with a new communications network, which launched that afternoon: Sukey.

The brainchild of a group of young, recently politicised computer programmers, Sukey's main goal is to stop people getting kettled. On the day of a protest, founders collate information from individual protesters – tweets, texts and GPS positions – about what is happening on the ground. The Sukey team then update an online live-map of the protest, accessible from smartphones. Simultaneously, they tweet and text brief summaries of events to all their subscribers, telling them where other protesters are situated, and – most significantly – where kettles are forming. As the nursery rhyme (from which Sukey takes its name) aptly suggests: "Polly put the kettle on, Sukey take it off again."

And, in London last Saturday, that might well be what happened. Around 500 students coming from a 5,000- strong anti-cuts march on Millbank joined the ongoing, separate protest at the Egyptian embassy. After around an hour and a half, a few demonstrators said they had overheard kettling tactics being discussed on police radios, and thought they had seen police lines closing in. They relayed this to the Sukey team at their computers in an east London office block, and the team quickly texted the news to their entire mailing list on the ground. Recipients of the text alerted those around them, many protesters left the area, and, perhaps as a result, no kettling took place.

One of the protesters who alerted Sukey to the potential kettle was Ben, 21, a member of last year's University College London (UCL) occupation, whose participants still form a fulcrum for the London anti-cuts movement. Ben is certain that Sukey played an important role in people moving quickly away from the embassy. "Everyone who was getting the Sukey updates was telling everyone who wasn't what was happening," he says. "It took about five minutes for us to mobilise."

There are, of course, other potential explanations for what happened: a genuine softening of police tactics; an existing awareness of kettling procedure among protesters; a police double-bluff; coincidence. It is also important to note that not everyone welcomed the presence of the anti-cuts protesters outside the Egyptian embassy. Sunny Hundal, editor of Liberal Conspiracy, argued that those protesters who had left an education-themed march to join a rally based around foreign policy were displaying a lack of ideological direction. This, coupled with the abusing of NUS president Aaron Porter, led Hundal to conclude that Saturday's protest "was when the student movement died".

Back at Sukey's secret nerve-centre in east London, however, the team are celebrating a measured success. "We'll take that as a win," says Sam Gaus, 19, a first-year computer science student at UCL, and one of Sukey's co-founders. There were kettles in Manchester and Edinburgh. But in London, for the first time in five marches, there was none. Coincidence? Gaus thinks not.

On 9 December, the day of the parliamentary vote on tuition fees, thousands of protesters were kettled in Parliament Square. Many of those present – myself included – were not aware until too late that they had either strayed from the march's designated route, or were in the process of being "contained". The result: students trapped for up to 12 hours; the supreme court trashed; dozens injured; 60 arrested. In London last Saturday, with no kettles, there were only nine arrests.

Sam Carlisle, 23, an electronics engineer who graduated from Durham, became politicised after his girlfriend was trampled in a horse-charge at the protest on 24 November. Outraged, he decided to offer his exceptional technical skills to the UCL occupation, where he met Gaus. To differentiate between the two Sams, other occupiers christened them "Sam the techie" (Carlisle), and "Techie Sam" (Gaus). Physically, the pair are chalk-and-cheese – Carlisle is pale and stocky; Gaus dark-haired and tall – but intellectually they seem united. The night before the 9 December protest, both independently came up with the same idea: a live, online map that could show people at home where protest troublespots were located.

"I came to Sam on the eighth and I said: 'I've got this great idea,'" says Gaus. "And then he showed me this flow-chart with exactly the same plan."

The map was up and running for the protest the next day, prompting excited praise from Guardian science writer Ben Goldacre and backhanded compliments from American security analysts. But though the map was an innovative development, because there was no way of quickly communicating what it showed to people on the ground, it didn't fulfil the Sams' ultimate goal: to help protesters avoid kettles.

So, over the next month, they set about coding what became Sukey: a text-based warning service (used to great effect on Saturday); a similarly successful Twitter feed; and an auto-updating map of the protest, accessible from smartphones, which users complained didn't update fast enough. A compass-based application for smartphones, which would have told users in which direction kettles were to be found, was not ready in time. It was not through lack of effort. By the time I arrived at Sukey headquarters on Saturday afternoon, Carlisle hadn't slept in a bed for a week.

Four other team members are also integral to the process. On the march itself was Amit, who spread the gospel of Sukey to every protester he could. Then there is Tom Bance, 22, a physicist at UCL, who sends out Sukey's texts. Matt Gaffen, 23, a freelance graphic designer, devises Sukey's visuals, and Bernie, a man with greying hair who looks too old to be a student is an IT developer – and Sam Gaus's dad.

As the afternoon unfolded, it was primarily Bance's job to work out what was happening on the ground. With Marie, another UCL student, he sifted through all tweets tagged with "#sukey". Once he was clear what was going on, he relayed the synthesised information back through Sukey's official Twitter and texts. When trouble started brewing at the Egyptian embassy, for example, Bance's text read: "LOTS of reports say a Kettle is about to be formed outside the Egyptian embassy. Stay sensible, stay safe. #sukey." If, as was the case, an area looks likely to be kettled, it is the Gauses who are tasked with delineating it on the online map. Carlisle, meanwhile, was desperately trying to finish the code for the compass application, and Gaffen was on hand to update any graphics that needed changing.

"We're like a busy newsroom," says Bernie. "We have to get information in, check it makes sense, and then get it back out again."

When Sukey's arrival was announced last Friday, some critics warned it would merely facilitate rioting, rather than help keep protesters safe. Tory blogger Harry Cole said in a tweet that he has since deleted: "Is there something discustingly ironic about riot organising iphone ap http://sukey.org/ Just about says it all about this country's kids."

Some announcements made by Sukey probably did indirectly assist those protesters who were less interested in the original "A-to-B" march, and more interested in a new kind of protest tactic that has emerged in the last few months: the "civic swarm", which sees large groups of demonstrators peel off from official marching routes and instigate flashmobs at shops such as Vodafone and Topshop, but which is arguably a perfectly justifiable form of protest.

But the Sukey team take umbrage at the idea that their goal is to cause disruption rather than to aid safety. They see themselves as distributors of information rather than battle tactics. Early in the day, they had sent out a text reminding everyone about the exact route of the march; later, they ended every announcement with the suffix: "Stay sensible, stay safe." When the march ended, and split into three groups of protesters, the team had a brief debate about whether they should carry on texting and tweeting. "We aren't there to lead people to the palace gates for the revolution," says Gaus Sr. By reporting the activities of the three meandering groups, he feared that "effectively, we're not just supporting it, we are instructing it". Eventually, however, they agreed that it is exactly at those moments that protesters are in need of information. "We're never going to be able to stop people leaving," Gaus Jr points out. "But when they do leave, and there is trouble – that's when we can be most useful. We can protect people from those troublespots."

Sukey is by no means the finished article. Though the events outside the Egyptian embassy seemed like a genuine success, plenty of people were frustrated that the compass-based application wasn't ready, and that the live map was either difficult to decipher, or slow to load and update. Additionally, since mobile phone reception is often scarce at protests, some complained that texts took too long to filter through. Carlisle accepts these criticisms: "I'm expecting people to come back and say it's shit, it doesn't work." But for him, it seems Saturday was almost a dry-run for future, larger protests, such as the Trades Union Congress protest on 26 March, which might attract hundreds of thousands of protesters to London.

But even if Sukey isn't yet working like clockwork, it appeared to have two effects on Saturday. Several activists said just the knowledge that such a communications tool was in operation made people more aware of the need to share information, and to keep in touch. Similarly, there was a sense inside Sukey HQ that their presence was, at least in part, making the police more careful about their behaviour.

It would certainly make sense for the Metropolitan police to pay close attention to Sukey: communication is not the police's strongpoint. On a day when students were keeping in touch by Twitter and mobile phone, the police were handing out little slips of paper. As Bance says: "The police don't understand Twitter. They might as well be shouting at the screen with a megaphone."

There is an argument going on about the part technology has played in recent protests across Europe and north Africa. But while it is lazy to brand these revolts "twitter revolutions", as Malcolm Gladwell and Evgeny Morozov have broadly argued, it seems equally silly to deny that social media does not have a role to play in facilitating protest and debate.

Sukey seems a prime example, and endorsement comes from an unlikely source: Tim Hardy, the founder of a blog called Beyond Clicktivism, and a self-proclaimed cyber-sceptic. Six months ago, sick of the excesses of social media, Hardy removed himself from Facebook and Twitter. "It was difficult to know what to listen to," Hardy says. "As Clay Shirky says, the internet needs more filters." But in Sukey, Hardy thinks he has found one such filter. He was so impressed by what he had seen, that by the end of Saturday he had agreed to be the team's spokesman. "It's really being used to enable something to happen," he says.

Quite what Sukey will go on to enable is not yet clear. The team plan to make their coding available to protest-minded programmers across the UK, but it remains to be seen what kind of impact it could have in, say, Egypt, where the government recently cut off the two keys to Sukey's London success: mobile and internet access. To stay ahead of the curve, Sukey will have to find ways round these problems. Protesters in Egypt have already improvised by using dial-up connections and new "speak to tweet" technology, which converts voicemail recordings into Twitter messages.

Further afield, international programmers from the Open Mesh Project are developing a system that turns laptops into temporary internet routers, and so allows protesters to communicate even without a conventional internet connection. But Sukey is unlikely to be behind the times for long. The team are tight-lipped about the details, but two of them say they might have found a way of doing without mobile reception. "We've got some ideas," says Gaus Sr, with a grin.