What is the correct market valuation for Apple Computer? The question is one of the hottest on Wall Street. The answer turns on the extent to which Steve Jobs, Apple's founder and chief executive, can convert the phenomenal success of the iPod music player into sales of computers, which account for the majority of the company's revenue.

Bulls are counting on a "halo effect". Under this scenario, consumers will be so impressed by the cute design and intuitive interface of their iPods that they buy Apple desktop and laptop computers, thus reversing the long-term decline of Apple's PC market share. At the last count, the California-based company held a mere 2 per cent share, the rest going to makers of PCs running Microsoft's ubiquitous Windows operating system on microprocessors mass-produced by Intel.