As I posted earlier, I tried to get insurance at the Greek border after crossing from Turkey in Feb 2006, but the lady who supplies tourist info there made a few calls and told me that Greek companies no longer sell green card insurance to foreigners.
I didn't try to get any in Italy, but in France it costs 90 euro for 3 days insurance. I didn't manage to get any until 6 months and 8 countries later, in Germany.
Organising it in Turkey would be your best bet if possible.
good luck and Mutlu Yillar,