New Yorker writer Susan Orlean does it. Cosmo editor Joanna Coles does it. About half the staff of creative agency SilverTech does it. Forget whistling; should we all be walking while we work?

The move is known as Project Momentum and will introduce new flexible working modes. Amelia Linzey, group chief executive, said most of the staff had left the seven-level Pitt St building where ...