More than just champagne and peacocks

"Many of our clients have Bloomberg screens on their desks and they know what's happening in the market in Hong Kong, Korea or Japan just as quickly as we do." The remark comes not from the head of a bank's foreign-currency trading operation or Eurobond sales team, but from Michael Tomalin, managing director of Barclays Private Banking.

It's a fair reflection on the rapid development of an industry that until recently looked upon providing a walker for a client's poodle as one of its most valued services. With almost $20 trillion in private wealth sloshing around the world, everyone is getting in on the act and established private bankers can no longer afford to rely solely on the Austrian millionaire art collector seeking to set up a discreet trust to shelter his family fortune from the ravages of inflation and currency volatility. He himself might be demanding discretionary advice on...