Remember your sandbox? That spot in your back garden or the school yard where you sat with a bucket and spade and modelled shapes in the sand? If the same space existed for young adults, what would it look like? Probably something like this.

Lisbon, capital of indebted Portugal, plays host to Sandbox’s first summit of 2012. A city looking for inspiration. Here an online community has come together in the flesh. They’re the Y Generation, not yet thirty, all doing something the rest of us aren’t. That could be fundraising to buy a bankrupt satellite to provide free internet in Africa, developing a traffic app for Egyptians, or launching a crowdfunded fashion website in France.

And that’s what binds them. Their fields might be disparate, their hometowns thousands of miles apart, but these youngsters are all freestyling their way to success. If Sandboxers had joined a graduate training programme, a path forward would be mapped out for them. Mentors would be close at hand. Training schemes automatically set in motion. But a start-up is a journey into unknown territory. To whom should you turn?

To each other, organisers believe. They’ve created a peer-to-peer mentorship system whereby people of like mind come together to share their experiences, advice, ideas and contacts. Real friendships are born. Business deals, says co-founder Christian Busch, are a secondary, but natural, consequence. He calls the process “accelerated serendipity,” explaining that the phrase you hear the most amongst Sandboxers is: “I really should connect you to...” All participants are already networked to the hilt. But events like the Lisbon summit help join the dots.

Participants lead the sessions. From martial arts to arts and crafts to “how ballroom dancing is like starting a business”, the idea is to equip Sandboxers with the skills to become role models in their fields, and the bonds to work together for a better future. "Imagine," says Paris Ambassador Rand Hindi, "if we’re all leaders one day, and we’ve already known each other for twenty years? "Organisers believe that as Sandboxers grow in experience, their close relationships will become even more valuable and effective in bringing about change. It’s an investment in tomorrow.

There’s also a lot of practical advice floating around. At one session on “Wonderwomen” (open to men too), we tackle the old chestnut of managing the work/life balance, and maintaining relationships over distance. Productivity evenings to deal with those tasks you’re avoiding, suggests one person. Split your schedule into focus, buffer and rest days. Schedule a stopover to catch a friend. Know when to switch off and spend time with real people.

It’s a privileged dilemma to have, and an example of the transformative power of technology in business and friendship. Sandboxers are a new breed of geek. Perma-connected but socially agile, always on the move, humping their laptops from country to country, they’re addicted to Skype and Gmail, WhatsApp and Viber.

Sandbox is an antidote to that lonely life on the road. The new technologies its participants access, including a private social network, are already of course social. Topics range from favour-asking to deeply personal conversations. But more than that, a community stretching over 45 countries with 16 hubs worldwide, in cities like San Francisco, Paris and Zurich, always has its arms open. Whenever a Sandboxer rocks up, their local ambassador throws a dinner, there’s a couch to sleep on, and the visitor plugs straight in. As Digital Foresight Strategist and globe-trotter Rahaf Harfoush says, “there are many networks out there, but this is the only one that has a heart.”