When it comes to a flutter, the British are not shy. Some £70m was wagered on this year's world famous Aintree steeplechase. And with the advent of the National Lottery, an estimated 90% of British adults now gamble.

All of which is good news for the surging number of online gambling sites that are busy fighting for a slice of the potentially lucrative UK market.

Online betting is a multi-million dollar business, especially in the United States, which is home to half the world's Internet users. As with most forms of e-commerce it is boom time. According to estimates, the global market will be worth $10bn in 2000 - and $20bn by 2002.

Viva Las Vegas - but not if online betting has its way

Scores of sites have been springing up around the world to meet the growing demand.

Taking part is simple. Anyone with a credit card can set up an account with a site, leaving them free to place bets on sporting events, or join a virtual casino (no jacket required).

Steve Abboud, whose company Global Entertainment licences online betting software to sites such as Vipsports, says eventually the industry could overtake the likes of Las Vegas and Monte Carlo.

"The revenues from gaming alone already dwarf those generated by the media, recording industry and movie industry. When you put that together with the Internet it's a very potent force," says Mr Abboud.

Threat to outlaw

He estimates medium-term growth rates for his company in the range of 200-300%, although this sort of talk will do no harm to the share price.

But unlike other online success stories such as Amazon and eBay, a black cloud hangs over Abboud's empire, in the form of the Kyl Bill.

Jon Kyl, a Republican senator, wants to outlaw Internet betting in the United States for good. Although his bill has been thrown out by Congress once already, Mr Kyl remained undeterred and last month announced plans to reintroduce the proposed legislation, with a few amendments. Mr Abboud doesn't rule out the chance of it being passed.

Black jack can be played over the Net

In fact, stringent gambling laws in most states already forbid online betting services from setting up in the US.

Global Entertainment and other such companies get round the law by setting up their operations offshore, usually in the Caribbean where gambling laws are more relaxed.

But the Kyl Bill seeks to go an important step further by punishing any punter who dares place a bet on the Net. Sen Kyl wants to see a $500 fine or 90-day prison sentence slapped on offenders.

But Mr Abboud says prohibition would be unworkable, as well as unfair.

"[Kyl's] supporters are the National Football League, and the Nevada Gaming Commission and the Atlantic City Gaming Commission. They just want to look after their own business."

UK to wait and see

The debate in America reflects a general uncertainty in many developed economies. While Australia, New Zealand and Germany have opted for regulation, others, such as Britain, have chosen to hang fire.

In fact, the UK's relatively liberal gambling laws would make it simple to establish an online bookmaker, although casinos would be completely out.

All you need is a credit card to set up an account

Tom Kavanagh, of the Gaming Board for Great Britain, which advises the government on gambling issues, says current policy is against "commercial gaming" in the home because of worries about addiction.

"We could rule it out entirely or tax it and regulate on the basis that if you prohibit it will just go underground," says Mr Kavanagh.

Paul Bellringer, director of Gamcare, set-up to help compulsive gamblers, fears online betting will prove especially attractive to the young, where gambling addiction is already a major problem.

"Seventy-five per cent of adolescents gamble. Young people are particularly adept at using the Internet so its possible that this will be more an allure to them than older ones," says Mr Bellringer.

One study, conducted by a professor at Harvard University in the US, concluded that within 10 years youth gambling would be a bigger problem than drug abuse.

Rather like Internet pornography, making an online wager is an anonymous business, so the stigma of addiction can be hidden, says Mr Bellringer.

Protect yourself

And if you were to lose your shirt in an online casino, how could you be sure it wasn't a fix?

Gambling the "sociable" way - in a betting shop

Mr Abboud advocates a range of safeguards. He advises site operators to monitor their customers' accounts for loss rates, and include a link to Gamblers Anonymous.

He also recommends thoroughly screening potential account holders to check their age, although this would be easier and more reliable with government co-operation, he says.

He concedes his licensees, which operate out of Curaçao, in the Caribbean, cannot be forced into complying. However, they are encouraged to sign up with the Interactive Gaming Council, a self-regulatory body which sets out a voluntary code of conduct adopted by many casinos.

While gambling addiction is on the rise in the UK - Gamcare estimates there are about 1.5 million "problem gamblers" in Britain - the signs are that online betting has yet to take-off seriously.