With no building of its own and a production record which has seen around 200 shows performed in almost as many venues, the National Theatre of Scotland (NTS) could be the very definition of the "pop-up" ethos of the 21st century.

True, the company and its work are regular features at more traditional theatre spaces - its trilogy of James Plays will occupy the capital's Festival Theatre for most of this year's Edinburgh International Festival - but alongside this is a commitment to breaking down the barriers between audiences and performers, and democratising the theatre experience.

In this, NTS joins a growing trend for "immersive theatre", where audience members become part of the show and the production itself is taken out of the traditional theatre space and into another arena entirely. For recent NTS productions such as Dear Scotland, that meant the Scottish National Portrait Gallery in Edinburgh. In the case of The Great Yes, No, Don't Know Five Minute Theatre Show, it's cyberspace, an increasingly important "venue" for the national company.

Building on the success of three previous projects in which five-minute plays from amateurs and professionals alike were broadcast over the internet, NTS has asked aspiring actors and playwrights to create works based on the idea of independence. And for 24 hours, from 5pm tomorrow, the results will be broadcast to the world in the form of 180 playlets featuring 840 performers from eight countries. Curatorial control of the project was given over to playwright David Greig and the late David MacLennan. The veteran producer was terminally ill when he took on the job and his death nine days ago adds poignancy to tomorrow's online theatrical marathon.

Beyond the subject matter, the only proviso was that each piece be shot in front of an audience of some sort and come to the NTS unedited, so it can be broadcast "as live". Some people, however, are dropping the "as" bit and actually performing their five-minute theatre pieces completely live, either in one of several NTS "hubs" which have been set up around the country, or via the company's roving camera crews. There will be seven of these, consisting of a camera operator and a streaming technician who will use whatever broadband facilities are available in the location. It could be a kitchen, a toilet, a garden. One person even plans to broadcast to the world from the end of the pier at St Andrews.

If it sounds like a technical and logistical nightmare, that's because it is. The people given the task of making sure it all runs smoothly are Seth Hardwick, NTS's video producer, and project manager Jo Walsh.

On the technical side, Hardwick has had to endure "a lot of days of hair-pulling" as he tries to come up with the best way of doing what sounds difficult even on paper. "There are a great deal of ways of streaming live, and a lot of them are to do with streaming yourself. But multi-user streaming, where we enable other people to stream to us and then we mix that and broadcast it out, that's where the challenge really lies. So we were auditioning the technology to ask if it could do the things we want it do to - because the most important part of this is the audience."

Those five-minute plays which have already been committed to celluloid, as it were - in reality a digital file that can be uploaded to the internet when the time comes - have been shot on a variety of devices, some producing broadcast-quality pictures, others the sort of footage you'd get from a smartphone.

"As long as it's recorded live in front of an audience with no edits, then that's OK. It is theatre," says Hardwick. "The important thing is that the camera is an audience member, it's a witness. We don't want to see the new Spielberg. We just want to see some theatre done to an audience. If they're filmed brilliantly, all the better. But we have people filming them with iPhones, some with small Handycams, and that's the joy of it - anyone can film on anything."

Unlike in previous Five Minute Theatre projects, this time the majority of the plays will be performed live. Entrance to the hubs is free and unticketed and, though performances can only be broadcast from a hub once every 30 minutes, each hub will be showing the (hopefully unbroken) web-based stream. "Juggling all the participants has been hardest part," says production manager Walsh. "We have a lot of first-time writers and actors."

In Glasgow, the live hubs are in Oran Mor, which be hosting performances from 5pm tomorrow, and the Citizens Theatre, which picks up the baton on Tuesday. In Edinburgh, the venues are The Village pub in Leith and Edinburgh College. There are further hubs in Aberdeen's Lemon Tree arts centre, at the Eden Court Theatre in Inverness and at the Electric Theatre Workshop in Dumfries, where the town's Electric Theatre company will be performing.

"They're a production company that actually originated from a Five Minute Theatre piece in 2011," says Walsh. "They have an amazing space in an old shop in the centre of Dumfries, and there's a lot of footfall so they're going to have quite a big presence. People walking past can just go 'Oh what's that?' and pop in."

For Hardwick and Walsh and everyone else involved in making sure it runs smoothly, The Great Yes, No, Don't Know Five Minute Theatre Show means a long night and fingers crossed. For those watching on smartphones, tablets or laptops, it'll be proof at least that theatre is about more than just curtains and clapping and fold-down seats. But for those participants who are empowered enough by the experience to want to continue writing, acting or making theatre, it could really be life-changing.

And what more could you hope to achieve in a day?

The Great Yes, No, Don't Know Five Minute Theatre Show runs from 5pm tomorrow until 5pm on Tuesday, www.fiveminutetheatre.com