What would it take for you to take off all your clothes in front of thousands of people? A million dollars was enough for Juan James Rodriguez, who took up the bet offered by American billionaire Alki David to become the first person to streak in front of President Obama at a rally in Philadelphia at the weekend.

There again, $1 million would probably be quite tempting for a lot of people: not least as rather too much booze and shameless exhibitionism are all that is generally required. In the early days of streaking - the '70s and '80s - the cameras tended to linger lovingly on streakers, especially the women, but now they tend to pan away quickly. "No one wants to give any extra publicity to them, " says BBC football commentator David Pleat.

Yet there is no sign of any let up in the numbers prepared to drop all for a moment's attention. At the Ryder Cup earlier this month, a man wandered on to the green, wearing nothing but a sun hat, red cape, socks and shoes and a G-string. And at the Carling Cup game between Scunthorpe and Manchester United one ran in wearing even less, to the delight of the home fans who chanted, "Fergie, Fergie sign him up. " Goldie now has his own Facebook fan site.

The first recorded streak was done in 1799 when an unknown man accepted a wager of 10 guineas to run naked from Cornhill to Cheapside in London. However, it only became a modern cultural phenomenon in 1973 after a mass nude run by students at the University of Maryland. The following year, a 25-year-old Australian, Michael O'Brien, stripped off during an England v France rugby international. The resulting photograph of O'Brien with arms out-stretched being restrained by a couple of policeman while a third placed his helmet over his privates, achieved iconic - almost biblical - status.

Certainly since then, streaking has been a recurring feature of sporting events throughout the world - though mainly, it must be said, in those countries with strong Anglo-Saxon affiliations - with both men and women equally keen to make a spectacle of themselves, though women are more likely to keep the lower half of their bodies covered.

The first woman to achieve any lasting notoriety was Erica Roe, who ran topless in a London stadium during an England vs Australia rugby match in 1982 after accepting a dare from a friend. This time the policeman's helmet covered a breast in another photo-opportunity that travelled the world. "I blame my elder sister Sally, who was going with a clutch of rugger-bugger friends and roped me in, " she said some years later.

"We were getting a bit bored, thought we should do something, and within seconds had decided to streak. It was an impulse thing. We threw our clothes off. I handed my bra to some people behind me - and my packet of Marlboro. Half-time arrived, and off I went. I remember running like hell, knowing I was being pursued and looking back for Sarah, who didn't join me. I heard all this screaming and thought, 'I have to get off, the second half is starting'. But I quickly realised the roar was for me. Then, of course, I behaved like an egotistical bitch, put my arms in the air and went, 'Yes! Hi!'" The tabloids went mad for a week, but Roe herself decamped to Portugal to grow sweet potatoes and live the quiet life.

Not that anyone really expects to make a career out of streaking. Jacqui Salmond, who stripped in front of Tiger Woods at the 2000 British Open, now works in a charity shop. At the time she was a lap dancer working in a pub in Kirkcaldy and had been watching a golf tournament on TV. "The whisper of the commentator and polite applause were enough to send me into a coma, " she later said. "I knew what would get the crowd excited. A streaker. And who better than me? I wasn't shy about flashing a bit of flesh. I burst through the cordon and legged it towards the 18th hole. Adrenaline raced through me. For a moment there was silence, followed by a few gasps and titters. Then everyone started cheering. Egged on by the crowds I even did a little victory dance. "

Even in the US, where streaking is often also used as a mild form of political dissent, it's still classified under naughty but somehow nice. In fact, just about the only place you are likely to come to grief as a streaker is if you're a male at an Australian sporting event. For some reason, Australian sports stars often find the sight of men running naked on to their place of work as an affront to their own sexuality and feel the need to wrestle them heavily to the ground. The truth is, no one is really offended by streakers any more. They get a brief mention in the press, a small fine, and then go back to their lives.