I am parked at a restaurant in an upmarket suburb, waiting for my daughter. An attractive young woman approaches. "Hi there," she says, huskily. I realise she is a prostitute and respond with a no-thank-you hand signal. She walks away, unhurriedly.

Like the memory it evokes of "sex workers" lining the main street from the centre of Cape Town to the fashionable holiday suburb of Seapoint, the scene is a sign of the sexual revolution in South Africa.

Once a bastion of austere Calvinism, it has moved decisively away from the prescribed sexual morality of the apartheid era, in a shift signalled by a recent court decision decriminalising prostitution.

Only the residue of the omnibus apartheid Sexual Offences Act, which criminalised interracial sex and marriage, proscribed homosexuality and outlawed prostitution, remains on the statute book. Known as the "Immorality Act", it has been stripped of its racially offensive clauses.

One of the reasons the High Court gave for its decision to decriminalise prostitution - defined as carnal intercourse for which the woman receives "pecuniary gain" - was a Constitutional Court judgment that the criminalisation of "sodomy in private, between adult consenting males, unfairly breaches their rights to sexual orientation, equality, dignity and privacy".

As the Constitutional Court judgment was silent on the issue of "pecuniary benefit" for one of the consenting males, the High Court has said "it cannot be contended that sexual relations between a man and a woman in private constitutes criminal conduct merely because money changes hands."

Another reason for decriminalising prostitution is that the law as it stands breaches women's right to equality. The law provides for punishment, including imprisonment, of women who accept money for sex but condones by its silence the men who offer money for it.

Two cases before the High Court show that the sexual revolution associated with the political upheaval is not over. The applicants in both cases are lesbian judges. One, Anne-Marie de Vos, is seeking a court order recognising the right of her same-sex partner to become an adoptive parent of her children. The second, Cathy Scatchwell, is seeking the same rights for her same-sex partner of 14 years as those accorded to the spouses of judges married to partners of the opposite sex.

Meanwhile, the judgment that decriminalises prostitution has raised questions about the continued prohibition (in theory, if not in practice) of soliciting and keeping brothels. The judgment favours the status quo, holding that women's advertising of their sexual wares intrudes on the rights of ordinary citizens.

But pressure for the next phase in the sexual revolution - emancipation of sex workers from outmoded restrictions - is growing, fuelled in part by the empowerment of women since the ANC came to power.

A central and increasingly articulated argument for legalisation rests on two propositions. First, that by bringing sex workers within the law, the government will be able to insist on minimum levels of health and hygiene in brothels. Second, and critically, that government will thereby strengthen its armoury in the fight against AIDS.