'Distributed Computing' is one of the most interesting computing phenomena of recent years. Millions of people voluntarily take part in projects that use their computers to aid scientific research.
The original, and by far the widest used, is the Search for Extra-Terrestrial Intelligence, with over 4.5 million users worldwide. You can find out more at http://setiathome.ssl.berkeley.edu/.
The basic rationale of these projects is simple. Home computers have immense, rarely used calculating power. Across the globe, at any one time, millions of computers are turned on, but doing nothing. If you can find a way of distributing data to each machine, and then analysing it, this untapped resource of computing power can be turned into a 'super computer' more powerful than any single machine out there.
The benefit for those taking part at home, beyond pretty screensaver images of the data being processed, is the knowledge that ordinary people across the globe are taking part in genuine scientific research that could make a difference to people's lives.
The use of computer networks like this hints at the potential for technology to transform our lives. For instance, any truly democratic society would require the population to have ready access to information to help facilitate discussion - the internet would be an ideal way to improve this.
Currently access to the internet is restricted to those who can afford it. While almost half of households in Britain have access (according to a report at www.statistics.gov.uk/pdfdir/inta1202.pdf), the web is very limited elsewhere - only 7 percent of the Russian population are online, less than 1 percent in Pakistan are and so on.
Ultimately though, in a world where more than one in six people lack access to safe drinking water (www.unep.org/wed/2003/keyfacts.htm) internet access shouldn't be the first priority. But if we dare to visualise a better society, we should begin to look at how technology could really be used to make that world work.
(Thanks to Nick in Cambridge for suggestions for this column.)