When I was at university, there was a student-run organisation called the Straight Line Society which I never quite got round to joining. Its members would draw a straight line on an A-Z and then walk that line as accurately as they could, even if it meant negotiating their way through private houses and gardens. A few years later I realised that this society, whether it knew it or not, was practising the art of psychogeography. As first defined in 1955 by Guy Debord, co-founder of the French Situationist movement, psychogeography reinvented aimless walking as a revolutionary act. The Situationists would cut up maps of Paris, reassemble the fragments and then walk the amended routes, in search of a new awareness of the city not driven by the repetitive routines of work and the daily commute.

Psychogeography is now enjoying a second life online, among groups of enthusiasts who explore the strange beauty of mundane city sites and write about their adventures. They are people like the Manchester Zedders, who stick a pin in an A-Z, head off to explore that map square and then blog about it; or the Loiterers Resistance Movement, a Mancunian artists’ collective which uses the blogosphere to organise rendezvous and share experiences. So far the LRM has held a “Subverting Surveillance Night” and attempted to “dematerialize” Manchester’s new Beetham Tower on the Winter Solstice in 2006 – a sequel to the legendary attempt to levitate the Manchester Corn Exchange a decade earlier. Their commonest tactic is the Situationist dérive, or purposeless drift through the city. On the first Sunday of each month they go for a ramble around the unregenerated parts of Manchester, on one occasion ending up in an underground car park and holding an impromptu concert with an orchestra of kazoos and tambourines.

The same desire to subvert the corporate takeover of urban space is evident in Remapping High Wycombe, a project run by Cathy and John Rogers, a brother and sister team of “psycho-crypto-topographers”. They wanted to make an imaginative record of the old town centre just before it was redeveloped as part of the inevitable “mixed-use retail-driven scheme”. The Rogers duo pioneered the use of an algorithmic dérive in which they repeatedly followed the same set of simple instructions, like “take a left and then a right,” to see where it led them.

But my favourite online psychogeographer is John Davies, a Church of England vicar who spent two months walking the length of the M62 motorway and blogging about it with his laptop from the wi-fi areas in Travelodges and service stations. The aim was to give himself “plenty of time and imaginative permission to explore the joys, riches, and complexities to be discovered in each good English mile”. You may have seen Davies in a disappointingly brief appearance in Michael Smith’s recent BBC4 series Drivetime. It wasn’t entirely a meeting of minds, mainly because Smith wasn’t feeling very psychogeographic. He was going stir crazy after several weeks on the road, and was just about to deliver a long rant to the camera about budget hotels.

The tone of these bloggers is quite different from literary psychogeographers like Iain Sinclair and Will Self, who use the weight of their erudition to reveal the city as an intricate maze of hidden histories and surreal connections. Partly because of the nature of blogging, the online psychogeographers tend to be more collaborative and tentative, more willing to explore mundanity for its own sake. For them, the city does not yield up its psychogeographic secrets readily; sometimes a bus shelter is just a bus shelter, not a site of ancient or occult significance. Most of them have come to psychogeography by accident, only discovering they were practising it after the event. The Loiterers’ Resistance Movement say that they still cannot agree what psychogeography is but that they “like plants growing out of the side of buildings, urban exploration, drinking tea and getting lost. Gentrification, advertising and blandness make us sad. We believe there is magic in the Mancunian rain. Our city is wonderful and made for more than shopping.” You don’t have to be a Situationist to say Amen to that.