This week on Taking Stock Susan Hayes Culleton talks to Tom Calver of the Times and the Sunday Times about how the iPhone has the most astounding supply chain.

Susan is also joined by PWC Ireland Parner Barry Whelan to talk about the best time to reinvent your business.

Plus, the economics of going to gym; Susan talks to Conor Pope of the Irish Times and Leslie Giltinan of 'Lean with Lesley' about the changing nature of people's exercising routines.