Reading in an F-shape

Jakob Nielsen's latest Alertbox suggests that people read web pages in a shape resembling a letter F: one horizontal line across the top, a second horizontal line lower down, then a vertical scan up (or down) the left edge.
Two of Jakob's three conclusions are just your basic 'inverted pyramid' thinking: 'Users won't read your text thoroughly' and 'The first two paragraphs must state the most important information'. But the third is new and a bit more challenging: that you need to put the important keywords at the start of subheading, paragraphs and bullet points.