OF ALL the gurus in India's menagerie of holy men, fakirs and wandering saints, Sai Baba, he of the spongy Afro hair, probably has the widest following - 30 million devotees spread around 100 different countries. So the celebrations for his 70th birthday this Thursday are inevitably going to involve more than just a slice of cake and a few party hats.

Jet-setting heiresses, pop-stars, New Age accountants and computer programmers from the West will be mingling with an expected 2 million doting rural Indians who are making the pilgrimage to Sai Baba's Puttaparthi ashram, in the south Indian state of Andhra Pradesh. Although Sai Baba lives simply (his bedroom in the Prashanti Mandir temple has only a cot, a dressing table and a portrait of himself in what followers believe was a previous incarnation: the famous guru from earlier this century, Shirdi Sai Baba), his Puttaparthi ashram is not just a place of spartan contemplation; instead, it's a lavish spiritual theme park, a Disneyland for the soul, with VIP quarters, a "spiritual museum", a helipad, a $20m hospital, and a university. (The colossal cardboard cut-out in the photograph on the right was specially commissioned in honour of Sai Baba's birthday.)

Sai Baba has a reputation for being a conjuror of miracles. It is said that when he was a boy, he one day threw away his schoolbooks. When his enraged father went to beat him, the young boy reportedly scooped up jasmine flowers and flung them in the air. The petals floated down to form the words "Sai Baba". Then the child, whose name was Satyanarayana Raju, is said to have left his village and begun to preach.

Sai Baba has now built up a multi-million pound empire, with more than 15,000 centres around the world. He probably has more followers than do the Anglican and Catholic churches of England; many of them insist that Sai Baba has cured thousands with incurable diseases. Among sceptics he is better-known for his habit of giving his rich devotees Japanese-made gold watches plucked "miraculously" from nowhere, while poorer visitors have to make do with a few pinches of sacred ash.

Sai Baba may be in need of some birthday cheering-up. Several years back, an Indian television crew filmed the guru producing a "miracle" watch - gold, of course - for a prominent Indian politician. When the crew went back to edit the film, the camera reportedly caught what the eye couldn't: Sai Baba moving, deft as a magician, to grab the watch from beneath a plate where it had been hidden and present it to his impressed guest. When the existence of the film became known to higher-ups in the television company, it "miraculously" disappeared - but not before video copies had been circulated.

Two years ago, several of Sai Baba's devotees knifed to death the guru's personal assistant, Radhakrishna, for reasons which are still not clear (police gunned down the killers). Sai Baba has refused to comment on the murder; he was not required to give evidence.

Birthday celebrations for the cherubic-looking guru have already been going on for months, as thousands come for blessings, leaving behind flowers and cash donations. In a land where there are many holy men, and an even greater number of conmen preying on the spiritually gullible, the gurus who succeed are those who can spread their teachings to the West. Few have succeeded as well at this as Sai Baba, with his halo of fuzzy hair and his airy miracles. !