DIAMONDS ARE FOREVER - just ask Hong Kong's tai tais and tycoons. At a recent South Africa Ecstasy Diamond Party, co-hosted by the Diamond Information Centre and Chow Tai Fook Jewellery at the Inter-Continental Hotel, tycoons Stanley Ho Hung-sun and Cheng Yu-tung, of New World Development, made a rare foray into the limelight. Perhaps they were looking for something special for that someone special. At one point, Cheng was surrounded by 10 models wearing $50 million worth of sparklers. Some guys have all the luck. The night was also lit up by Joseph Lau, Charles Ho and Yvette Yuen.