Barry Ritholtz helps put Greece in perspective:
All by itself, the insolvent nation-state of California is the 8th largest economy in the world. Its the size of France. According to the CIA Factbook, Greece is number 34. That is a lot of hyperventilating about a relatively small impact to global GDP. Italy is 11, Spain is 13, Portugal is 50, and Ireland is 56.
Additionally, in the US, we have 43 of the 50 states in some form of financial distress.