Take the following as a health warning. I've spent the last month in South Africa, but I was not reporting from there. I was in the country on a writing break, with my ears and eyes open, but without ever using my notebook in anger. What I picked up were impressions, rather than a firm, detailed analysis. I know, as the nerds like to say, that the plural of anecdote is not data - and what I have very much falls into the former category. That's the disclaimer. Here's the unscientific conclusion: I was disappointed.

I fall into the generation for whom apartheid was the dominant international cause of our youth. If baby-boomers were galvanised by Vietnam, then those who came of age in the 1980s were inspired by the campaign to transform South Africa. Even if we were not manning the 24-hour picket at Trafalgar Square, apartheid formed a kind of backdrop to the times. Cry Freedom was on at the movies, Free Nelson Mandela was the anthem at every college disco. What Thatcherism was at home, apartheid was abroad: the issue of the age.

That was nearly two decades ago. I assumed that a trip in the winter of 2005 would be to a wholly different country, with apartheid and all its works a bad, fading memory. That's where I was wrong.

Of course, and as everyone knows, the formal structures of that dreaded system have long gone. The country is ruled by its second black president; "Whites Only" signs are to be found behind glass in a museum and nowhere else.

And yet, the rainbow nation, the "new South Africa" so constantly invoked and effectively publicised, proved elusive. What I found, during what one scholar calls the "banal encounters" of day-to-day life, was a set-up remarkably like the one I had imagined back when I was a student shaking a bucket for the anti-apartheid movement.

If you saw a smart car, its driver was white. If you saw a smart house, its owner was white. Its cleaner and gardener were black. This was not "many" or "most". This was all. After a while, I made a little wager with myself. Would I see, at any point in nearly four weeks in the country, a white person serving a black person? I looked hard - at restaurants, at petrol stations, in bars, in shops, in banks. I never saw it. Not once. I looked at magazine covers and window-displays in clothing stores. White, white, white. Occasionally, there would be a token black face, usually very light-skinned.

I would ask white South Africans I met about this. Sometimes they would be defensive, insisting that Britain or America were not much better. It's true: photo displays at Gap or Marks & Spencer might also have just one or two black faces. The difference is, Britain has a non-white population that accounts for no more than 7% of the whole. In the US, African-Americans make up about 13% of the population. Yet three in four South Africans are black. Looking around, you'd have thought the reverse was true: that this was a white country, with a small, tolerated black minority.

Others would tell me that I needed to get out more and they were surely right. I did not travel much beyond Cape Town and I am ready to believe that other cities - with Johannesburg the chief example - are advancing much more rapidly. Nevertheless, it was striking to see how often, outside the realms of formal politics, power and privilege remained in white hands.

Cape Town itself was a shock. It is stunningly beautiful, a city framed by mountains, two oceans and big, blue skies. All around were people having relaxed, unending fun. It was not just the tourists: local people, too, seemed to treat the city as a playground. When they weren't surfing or hang-gliding, they were sunbathing or heading off for a round of golf. During the daytime, the cafes would be full, made noisy with local accents: people with time on their hands and money in their pockets. White people to be precise - their tables cleaned, their cars watched, their shirts ironed, their coffee brewed by black people, most of them paid a pittance.

Ah, but this is not apartheid, I would be told. It is an economic, rather than a racial divide - the same gap between rich and poor one might find in any country. Is California so different, where affluent whites are pampered by Hispanic maids, janitors and valet parkers? Is Britain so much better?

Well, yes. Because while economic and racial dividing lines often map on to each other elsewhere in the world, in South Africa they seemed all but identical, entrenched by a long political history that makes movement across the divide punishingly difficult. I know there is a white working class in the country and that, conversely, a few black entrepreneurs are now emerging. But the overwhelming picture is of a society where the goodies are still hoarded by one group - and withheld from everyone else.

The government is doing its best, with a Black Economic Empowerment programme designed to spread the spoils more fairly. That has run into trouble though, with accusations that the chief beneficiaries have tended to be friends of the ruling elite, shutting out the majority of black South Africans. (On this point, one of the loudest critics has been the president's own brother, Moeletsi Mbeki.)

Nor is it encouraging that the African National Congress seems to have developed a thin skin when it comes to criticism. While I was there, Archbishop Desmond Tutu was locked in a very public row with the ruling party. He accused the president of surrounding himself with yes-men, rewarding only sycophancy and punishing dissent. Mbeki shot back, questioning Tutu's respect for the truth and his right to speak about internal ANC matters when he is not a member. Later, the party branded Tutu an "icon" of whites, as if he were no longer an authentic black leader. It does not amount to a full case of Mugabe syndrome, far from it. But these are uncomfortable warning signs.

Of course, any fair account has to recognise, as a just-published state of the nation survey does, that South Africa has made enormous strides in the 11 years since apartheid. The country did not descend into civil war, and it is more peaceful and more prosperous than the sceptics ever predicted.

Nevertheless, my experience has forced me to think again about the pace of political change. While I was in South Africa, Nelson Mandela marked the 15th anniversary of his release from jail. I remember watching that moment on television along with the rest of the world. I thought then that the end of apartheid would bring an end to the crude inequality that made blacks the servants of whites. A decade and a half later and it has not. Change, I realise, is glacially slow. As Paul Foot wrote in his last book, revolutions do not take hours or weeks but many years - and sometimes even longer.