By Ryan Dilley BBC News Online

When walking city streets you can at least escape the barrage of poster ads and corporate logos by looking at the pavement, right? Well, not anymore. "1939 Returning" is the ominous warning scrawled in spray paint on walls across London.

Fortunately, the graffiti reference to 1939 - not a good year for many people - is not a neo-Nazi threat, but a bit of "guerrilla advertising" for a rock band, The Crocketts.

1939... still here

Though the band's single came and went in late 2000, some of the graffiti has stubbornly survived so as to still annoy, confuse or menace passers-by.

Record labels eager to court rebellious youth are not the only ones branching out from more traditional methods of street advertising - some major companies are now dabbling in "vandaltising", and giving it a new twist.

Graffiting walls is old hat it seems, so vandaltisers are instead daubing the very pavements on which we walk.

In the US last year, computer giant IBM used "biodegradable chalk" to leave mysterious symbols on the streets of New York, Boston, Chicago and San Francisco.

Think different, IBM

IBM then launched a poster campaign letting city dwellers know that the strange drawings were part of its attempt to promote a new PC.

The stunt backfired when street cleaners in San Francisco said the chalk "tags" were far from biodegradable and in fact took 200 hours to scrub off the paving slabs.

One man was arrested in Chicago for drawing the IBM logos and the corporation eventually coughed up more than �100,000 to placate enraged city officials across the US.

"It's a new brand of trainers, Ma"

Lingerie firm Gossard has now launched a similar exercise in "guerrilla marketing" in the UK - stencilling adverts for a new line of knickers outside radio stations, newspaper offices and publishing houses in London.

"They're done in completely washable chalk, we've been very careful about that," says Camilla Foster of marketing firm Yellow Door, who masterminded the campaign.

"Upsetting the authorities with graffiti might give you publicity, but not of the best type. The rain will wash away our chalk.

"People are swamped with billboards. This was a more subtle way of introducing the brand. And a lot cheaper. Firms which once feared getting into trouble, now find guerrilla tactics more acceptable."

Urban blight

Andrew Pelling, who chairs the graffiti committee of the London Assembly, is unimpressed by Gossard's tactics - fearing they won't help his effort to cut London's �100m annual graffiti clean-up bill.

"Though using chalk may be environmentally less damaging than spray paint, it's still not very helpful that a company should encourage the idea of defacing street furniture," he says.

It washes off, honest

Indeed, a recent London Assembly report on graffiti said companies "must conduct their advertising campaigns responsibly considering the wider environmental and social implications" and went on to recommend that the authorities "exert pressure on businesses on behalf of Londoners to observe these responsibilities".

While Mr Pelling is not pleased with companies which graffiti - even by showing it in TV commercials or borrowing graffiti-type logos for posters - he reserves a special distaste for advertisers who pick up spray cans themselves.

"We often complain that young graffiti writers don't know the costs involved in clearing up after them, but companies should understand that expense," he says.

High risk

Veteran advertising executive Graham Singleton says he is "amazed" large firms with huge marketing budgets would risk using such guerrilla techniques.

"It can backfire. Most responsible firms wouldn't do it, but for some small companies trying to break onto the scene with a rebellious, fresh image it can pay back in spades.

A recent report by a UK marketing firm caused consternation by advising leading manufacturers to make their products more appealing to young people by giving them "criminal kudos" - partly through guerrilla marketing.

Own goal for Derby

"That can work as long as it fits the image of the company," says Mr Singleton. "If you're marketing to groups such as the over-60s graffiti would only turn your audience off."

Though seemingly "outlawish", UK advertisers using graffiti may not actually end up in trouble with the authorities.

The London Assembly grimly admitted in May it is the "generally held opinion that the courts and law enforcement agencies do not regard graffiti as a serious offence".

Indeed, some councils are not above a little vandaltising themselves. Derby city officials fighting illegal graffiti were left red-faced last month after an entertainment venue they run spray-painted ads on local pavements.

However, Roger Edwards, the Assembly Rooms general manager responsible for the ads was unrepentant. "It is a little bit of the guerrilla marketing to catch people's attention. To some degree it is graffiti, but it is done very stylishly."

Stylish or not, council workers were set to work scrubbing the streets clean.