DEVOTEES of Lan Kwai Fong's longest-running, Middle Eastern restaurant, Mecca 97, are urged to block book their reservations as it closes for good on June 19. Nichole Garnaut and Christian Rhomberg, partners in the 1997 Group, have decided the concept has reached the end of its natural life span after four years. Rising phoenix-like from the ashes of Mecca 97, will be a flashy new espresso and grappa bar to be known as either Bar Centrale, L'Modo Mio (my way in Italian) or Vendetta, complete with gleaming Gaggia coffee makers and tempting little Italian biscuits. Some might argue after more than 10 years in existence, the 1997 Group has become a Hong Kong institution. With its penchant for changing formats, Ms Garnaut and Mr Rhomberg seem to be saying they do not want to be confined in one. Once the coffee bar isup and running, Ms Garnaut is said to be ready to open another gay club in Central. IN their jacquard loom, silk ties and grey flannel suits, the great and the good crowded into the China Club the other week to rub shoulders with Viscount Linley at what should have been an exclusive gathering. Princess Margaret's son was exhibiting a collection of $110,000 cigar boxes he was hoping to sell. Among those taking a close interest was a tubby, young Briton who enthusiastically told a colleague of ours how he was invited by sponsors Dunhill because he was on the company's A-list of customers. Waiters passing with champagne bottles were constantly collared by the man who wanted his glass topped up. The result was he started to become increasingly expansive about his life. He said he ran his own ''very successful'' business. Then he updated that to say he was in between jobs after being brought out from the UK to work for a publishing company. But he was sacked a few weeks later and was now owed $1 million. Later he revealed his business was doing rather badly. Slowly realising the man regarded truth as a fluid concept, our colleague applied the Hong Kong social litmus test and asked where he lived. ''Actually, I don't have a place of my own, I'm transient. I like to stay with friends all over the place, it is more exciting that way,'' he replied. So where are you off to tonight? ''Oh Tsim Sha Tsui, a little place I have there. It's called, now, letme think . . . er, Chun Hing . . . no, that's not right. Yes, I remember now - Chungking Mansions,'' his beaming face flushed with champagne. Needless to say, he didn't place an order for a humidor. AT a swish lunch for 24 impossibly wealthy tai-tais thrown by watchmakers Delaneau last week at the Marriott, eight of them splashed out more than $1.1 million between them to buy the diamond-encrusted timepieces at a mere $140,000 a throw. As you struggle to make ends meet before next month's salary cheque, it may be of some comfort to know there are still lots of Hong Kong people who never have such anxieties. IN the run-up to the mega-hyped Planet Hollywood launch tonight, the restaurant has been staging a series of dress rehearsal dinners to fine-tune their service. At one of them, B. S. Ong, the Singaporean who owns the Hong Kong Planet Hollywood franchise, bounded up to one table and exclaimed: ''You must try the desserts - they're all made by our kitchens and they're excellent!'' The party readily agreed, which was no surprise because one of the diners was Gerard Dubois, a partner in La Rose Noire restaurant. A mole in the catering trade informed us Mr Dubois and his team were baking six of the desserts on the Canton Road restaurant's menu, including brownies and Arnold Schwarzenegger's mum's ''home-made'' apple strudel. Apparently, La Rose Noire bought $25,000 worth of Snickers bars as well as 100 kilos of Oreo cookies to melt down for Planet Hollywood's Snickers and Oreo pies. The mole told us after honing his skills making delicate European desserts, Mr Dubois has informed friends the recipes will never reach his menus, which is just as well, considering Planet Hollywood made him sign a confidentiality agreement never to reveal their contents.