I've been following the Greece thing. It's interesting. On the one hand, you have reality: Greece is not Germany. Tax fraud is a national pastime. On the other hand, you have very rich people who want a single government in Europe (for now) that they control (dictatorship). Through careful fiscal engineering, we have the Euro and a European government structure where taxing and spending are not controlled by the "elected" officials, but the shape of banana curves or minimum size of carrots is.
To answer your question of what would Greece do without the Euro, they would go back to what they have been doing for the past several thousand years: Use their own money. There are rumors that the bills are already printed. Greece has traditionally used fiat (it's money because I say it's money) money and run a nice inflation scam. Being locked into the Euro would never work. They just borrowed and gave it away like they always did, but they couldn't inflate their way out of it anymore.
Look at the parallels: In 1918, the entire continent was intertwined with "I got your back" treaties, like a big ball of spaghetti. It took one little peon arch duke getting capped to trigger off a call on those treaties and a good chunk of the continent (and people) got turned to crap. Today, the entire continent (and rest of the world) is intertwined with financial "I got your back" treaties, like a big ball of spaghetti. If you don't follow it close, you'll not recognize CDS, CDO, MBS acronyms. It is a huge mess, including the U.S. financial system. A short analogy: Greece borrows 1billion euros (dollars, whatever) at 3% interest (not today, a year or two ago). The loaner (buyer of the bond) purchases insurance on that bond, so that if Greece doesn't pay, the insurance company will. That buyer is your pension fund. The insurance company is Goldman Sachs, who then buys insurance from someone else (Barclays, some German bank, etc.) on the insurance they sold your pension fund. The next bank buys insurance on that insurance, etc. At each junction, banks and bank like institutions take a little slice of the pie to pay themselves big bonuses (which the OWS monkeys or "useful idiots" have keyed in on). Now, what happens if Greece doesn't pay the loan back? They never have before. Well, then a chain of 8 bank like institutions goes under as each tries to get the capital together to repay your pension fund. Other banks won't do business with them because, hey, they got no money to pay your pension fund, how are they gonna cover these Portuguese bonds? The chain reaction would spread (they think) across the whole world and the whole world economy would grind to a halt.
This is why Greece was not bankrupted. Instead, they (the EU) rearranged the Titanic's deck chairs and said that your pension fund loosing 50% of the Greek bond value was not a default, which would trigger the insurance policy chain reaction, but instead just a minor rearrangement of terms or something and your pension fund had to agree to that, or else lose it all.
Meanwhile, the Germans are reminding everyone that the continent could go back to war again pretty easy. After all, Europeans have been killing each other for >1K years, why stop now? Under that threat, everyone looks the other way while Greece pretends to intend to do something about borrowing more money and never paying it back. The EU pretends that borrowing more money is the sure fire way to fix too much debt. Goldman Sachs pretends everything is great and sends its top executives to be top Obama administration officials.
Now, we pickin' on the People's Republic of California too? I lived there 18 years before escaping. Let 'em go, please.