What happens if you like smoothed lines instead of jagged pyramids? In his cautiously titled blog post "Beautiful But Terrible Population Pyramids", Jorge Camoes, author of the Excel Charts blog, proposes an alternative technique to the classical way of representing population pyramids. In his rendition of showing the distribution of various age groups in a human population, each series displays a population by age group (of both sexes) in a given year, from the year 1981 (darker color) to 2050 (lighter color).
It rather works well, as at the bottom of the post, he also demonstrates some properly labeled versions, showing the data divided by gender.
According to Jorge, this result was achieved through looking for a way to balance the effectiveness of the graph with "grabbing the attention of the viewer". In effect, these beautiful/terrible graphs are simply the result of removing the axes and labels, and replacing the traditional horizontal bars with some smooth splines.