Well then, here's an
excellent article from The Economist about the financial woes of Greece (and Europe).
The graph is also very illustrative. Greece's debt is more than 100% of GDP. For comparison, public debt in the US is somewhere around 50%.
The other country with a huge debt is Italy. In fact, its public debt as a percent of GDP is even higher than Greece. I read elsewhere that Italy's debt to France alone is about 20% of France's GDP.
I say again: stupid Italians.