Pictures can say more than a thousand words and statistics is using this principle with all kinds of charts everyday.
Two particularly interesting visualisations for development numbers are the Worldmapper and the Gapminder.
Worldmapper offers a huge selection of maps which show geographic territories sized in accordance to the chosen indicator. An example is this map that shows infant mortality:
Gapminderâ€™s approach is slightly different since Gapminders unique strength lies in the dynamics of the charts. Gapminder shows changes over time. To get a first impression of Gapminderâ€™s statistics watch the exciting presentation of Hans Rosling here.
For your own, homebrew statistics use the Google Gapminder implementation: http://tools.google.com/gapminder
It is great fun to play with these tools and they also show that some of the myths in development work are not correct any longer.