The financial world, especially in the US, is obsessed with comparing the present recession to the Great Depression. This is entirely wrong.
Economic conditions today have little in common with 1929. Economies are made by humans. Humans in China and India were virtual slaves, Japan was a minor power, most US trade was between Europe and US. There are many more human beings in the world today-and parts of the world which were irrelevant at that time, economically speaking, like China, South Asia, and even Brazil, are very important actors in the world economy. Trade between these countries and the rest of the world was very small; today it is the major thing in the world economy.
Since the state of the world was very different in 1929 than today-any comparison to that time is plain false. Unlike oceans and stars and mountains and other physical phenomena, which haven't change much in a couple of hundred years-economies, which depends on the activity of live humans, have changed considerably. We cannot compare two worlds so very different from one another in economic activity.
The US Fed Chief Bernanke is a so called expert on Great Depression. Einstein was an expert Physicist, and Darwin was an expert Biologist. The abilities of the last two are obvious, testable, and provable; the skills of Bernanke are closer to expertise in Astrology.