It is a practice increasingly being used by Australian couples who desperately want a baby but find the legal problems at home mean the US is the only place they

can pre-determine their baby's genetic make-up and overcome other obstacles.

Californian woman Allison Jarvie is one of hundreds of women in the US listed on the site.

Jarvie is paid about $10,000 every time she allows her eggs to be harvested from her body, fertilised and placed in the uterus of another woman.

So far her eggs have created three separate sets of twins, including children for an Australian professional couple.

The website is operated by The Egg Donor Program company, which has produced an estimated 2500 children around the world in the past 15 years by linking women that want to sell their eggs with infertile couples. The company's website lists 250 women who are offering their eggs for sale.

At first glance, the profiles look like something from a dating service - and, in some ways, that is exactly what they are. Only babies, not love, is on offer.

With a click of a button, potential parents are able to discover just how a child might look, and what they might become, if a particular woman's eggs were bought, fertilised and implanted in the mother-to-be.

Jarvie, 29, who has three children of her own, is just one of the women on that website.

Just over a year ago, her profile caught the eyes of a professional couple from Sydney aged in their late thirties. They want to keep their identity secret, but he is a very successful banker and she is also a professional.

For years they had been trying unsuccessfully to have a child.

In their desperation to start a family, the couple had even turned to a friend to donate eggs, but the procedure failed to produce a child.

As their prospects of parenthood began to fade, the couple put their names down to adopt a child. It was while they were on this waiting list they clicked on eggdonation.com and opened up a file on Jarvie.

It was a match. Jarvie had many of the characteristics that the Sydney couple wanted in a child and - over the next few days -

a series of phone calls were made between the couple and The Egg Donor Program.

A short time later, the couple were on their way to California in a final bid to have a family.

"They flew here for a consultation, they were shown my profile, they liked it and asked to go forward, and it happened straight away," Jarvie recalls.

Over a couple of weeks, the Sydney woman underwent a series of tests and was given drugs to stimulate the lining of her uterus, while Jarvie received injections that would stimulate her ovaries. Jarvie was later injected to start ovulation.

Then, in a 45-minute operation, eggs were harvested from Jarvie's ovaries, placed in a Petri dish, and fertilised with the banker's sperm for three days. Life was created.

The resultant embryo was then implanted in the Australian woman's womb and, a few days later, the couple flew back in to Sydney - their lives forever changed. Last May, the Sydney mother gave birth to a boy and a girl, who carry her husband's genes - and the genes of a woman who lives on the other side of the world.

The Egg Donor Program company estimates it has helped to create children for more than 200 couples living in NSW, Victoria, South Australia and Queensland. For many couples, the journey to the United States is a way to circumvent the long waiting lists at home for egg donors and laws against paying for donors and surrogate mothers.

Most of the couples have kept their trips to America secret from even their closest friends. The buying of eggs and surrogacy is a moral and social minefield, raising ethical questions about the buying of life, and even the basic issue of determining the legal status of the mother of a child born from a donated egg and borne by another woman. But for Jarvie, who now works for The Egg Donor Program, there are no such dilemmas.

"The mum is the one that gives life to the child," she says.

"Without her carrying the child, there wouldn't be a child - she gives the blood, the oxygen and the food, I'm just the DNA."

It is no coincidence that the couple who bought Jarvie's eggs are well off, because buying eggs is expensive, with Australian couples spending up to $20,000 for a "harvest" of up to 10 eggs from a donor. Then there is the cost of the in vitro-fertilisation procedure, which includes the fertilisation of the eggs and the implantation of the embryos in another woman. That process can add another $30,000 to the bill.

And for couples wanting a surrogate mother to carry the embryos and give birth to the child, that costs another $130,000.

On top of all that is the cost of airfares and accommodation during the whole process.

Another leading Los Angeles fertility agency, Egg Donation Inc, says it has helped 50 couples from NSW, Victoria, Queensland and South Australia to have babies.

The company finds donors, organises the transfers to recipients and even finds surrogate mothers.

In the last 12 months alone, 10 Australian couples have visited Egg Donation Inc's LA office.

The person in charge of matching donors with recipients at Egg Donation Inc is Lyne Macklin-Fife. Sitting in the sterile boardroom of her office in Encino, LA, she explains that an emerging trend is for gay couples to use the company's services.

So far her company has helped 10 homosexual couples from Australia become parents.

She has another five on her waiting list, and there may be more after the company visits Australia next year to promote its service.

Macklin-Fife says the gay couples are invariably well off, educated and generally aged between 30 and 50 years.

Many are from the same social groups in Sydney or Melbourne and that in itself can create problems, with Egg Donation Inc having to make sure different donors are used for each gay couple to ensure the children look different and have different personality traits.

These new families are created by taking one of the men's sperm, fertilising donated eggs and implanting them in a surrogate mother. And Macklin-Fife says in many cases the men's families are very involved in the whole process, with mothers often helping their sons to choose the donor.

And, in almost every case, the men want to have twins.