Waterfall charts in style of The Economist with R

Waterfall charts are sometimes quite helpful to illustrate the various moving parts in financial data, particularly when I have positive and negative values like a profit and loss statement (P&L). However, they can be a bit of a pain to produce in Excel. Not so in R, thanks to the waterfall package by James Howard. In combination with the latticeExtra package it is nearly a one-liner to produce a good looking waterfall chart that mimics the look of The Economist: