The Greeks loved a bit of porn, the Roman's invented the orgy and there's even evidence of saucy cave paintings by our ancient ancestors. Why then, centuries on are pornographers shouting about new, unique and exciting forms of sex? Risking blindness in the name of serious investigative journalism Chris Wilson donned his rubber gloves and braved the mucky streets of Soho to find out what all the fuss is about.

The first thing that strikes you about Berwick Street, or 'Porn Alley' as it's more accurately known, is the fluorescent lights dripping from every shop, flashing at you and enticing you in. You're suddenly cast into a new world where sheepish middle-aged men shuffle around clutching shiny black carrier bags and eastern European women whisper saucy advances into your ear. Pounced upon by a South American-sounding girl, the price of £60 was offered for full blown sex. 'No thanks, I've got a girlfriend', I lied. 'Well, why don't you fack off then?', she spat sounding more cockney than Barbara Windsor.

Inside a phone box a fluorescent card promises 'beautiful women doing what you want them to do best', but I couldn't see a single photo of a beautiful woman doing my laundry. Don't know about you, but I can handle bad sex - creased jeans are in a different league altogether. Phone sex ads are prevalent, both in phone boxes and pasted all over the back end of any quality bongo mag. Phone sex is possibly the most useless and expensive thing you can spend money on. After all, if you were hungry you wouldn't ring up Dominos and ask them to read out the menu would you? If anything, talking for five quick minutes to Saucy Suzi from Monaco (read Mitchem) will leave you more frustrated than before. The end result? Mucky sheets, a hefty phone bill and an overwhelming feeling of self disgust.

On a comedy level, however, the graveyard of phone sex ads is pure genius. Lines like 'screw us before we're too old' (how long does it take?), 'sexual experiences featuring midgets' (would that be me or the other person?) and for rural types 'do me barnyard style' (lots of cow shit, then you get run down by a combine harvester) are funnier than they are sexy, and unlikely to get people reaching for their phones.

Contact mags, on the other hand, are flying off the shelves of smut emporiums as the seemingly desperate among us snare sexual partners using pen and paper. An extension to this, and a truly exciting new sexual forum, is Craig's List's Casual Encounters, a virtual contact mag for the filthy minded. Users of all ages and locations post their ads online and wait for the offers to come flooding in. Some ads are genuinely innocent (I am shy and curious...), others straight down the line (Doncaster man seeks horny woman...), while many are pure muck (I will take your cock AND balls in my mouth...; Touch me, suck me, lick me, f*** me...). You get the picture.

Most people here are looking for NSA (no strings attached) fun; brief encounters that benefit both parties equally. This all seems rather seedy and cheap, but Jimmy King (not his real name), a frequent 'user' of Craig's List and other contact web pages, believes that NSA experiences, rather than distorting traditional sexual practices in a sordid way, actually make sex pure and simple.

'Where nothing is taboo, and everyone knows exactly what they're getting into, there's no room for mis-adventure. It's just sex, a way of expressing yourself without all the other shit that goes with it. Some of the stuff on offer is really exciting and exotic but you wouldn't want to do it to your wife or partner... so you do it with a consenting stranger.'

Using forums like this to get your rocks off seems to be an increasingly popular service and is, to a certain extent, replacing phone sex lines and prostitution as a means to an end. Why pay for sex or virtual sex when you can have the real thing for free with someone who's as into it as you are?

'I've never used a prostitute,' claims King. 'Meeting people like
this isn't prostitution, it's harmless fun and it's free.'

So, there you have it, it's not porn that's changing, it's sex. Punters can get exactly what they want without dealing with Soho's foul-mouthed call girls or paying £5 a minute to talk dirty with bored, unattractive housewives. The streets are still as filthy as a gang of Irish navvies, but the new sex revolution is taking place right here on your computer. Go safe now.

Chris Wilson