If you fancy being in a riot, pop down to Queen Square in Bristol. You will be able to spot the people taking part: they are wearing stereo headphones and distinctive little backpacks, and some of them may have Compaq iPaqs in their hands. This is, after all, a virtual riot, the real one having taken place in 1831. But it has been recreated as the world's first "located radio play" as part of the Mobile Bristol project.
As you walk around the square, you hear different sound clips that imaginatively portray the experience of the riot, ended by a charge of dragoons. The system knows which clips to run because it knows where you are, thanks to GPS information. And while the play is meant to be enjoyable, it is also part of a research project that is moving the near future of computing out of the lab and onto the street.
Everyone has a good idea of what the next computing infrastructure will include. There will be lots of mobile devices, such as handheld computers, mobile phones and digital music players.
There will be (and in some places already is) ubiquitous wireless coverage: GSM, GPRS, DAB (digital audio broadcasting) and Wi-Fi, with Wimax to come. There will be location information from GPS and GSM, local Bluetooth access points, and perhaps embedded RFID (radio frequency identification) chips.
We know this. What we don't know is what we are going to do with it. Mobile Bristol is attempting to find out.
This world-leading project is driven by Hewlett-Packard's UK research lab (which is just outside Bristol), the University of Bristol, and Appliance Studio, with £1.6m in funding from the Department of Trade & industry. Other participants include the BBC, Ordnance Survey, the Royal College of Art, Inmarsat and Vodafone.
The basic idea, according to Phil Stenton from HP Labs, was to create an infrastructure and see what could be done with it.
Riot 1831 is just one example. I tried two more: a "tourist trail" application and a game. Harbour Trails, run with the Bristol Ferry Boat Company, provides a running commentary on the things you see during a harbour tour. In Savannah, an educational game, you are a member of a pride of lions. There are many more to come.
The key point about all of these projects is that they are experiments, not products. The idea is to find out what works and what doesn't, what people like and what they don't like.
In the longer term, of course, lots of people are interested in finding ways to develop profitable applications. Then companies such as HP will benefit from supplying the development tools, devices, servers and other systems that deliver information not just anywhere/anytime but to the right place at the right time.
Jack Schofield is computer editor of the Guardian