Do I need Euro before I leave the USA?
 

No. Take two ATM cards to supplement your crdit card.

Use your credit card as planned, and maybe use a <i>bank</i> ATM or debit card to withdraw local currency at each stop. Ireland, France, and Finland all use Euro.

Some people report that they have to have euro before leaving as they are too (what is the polite word?) incapacitated after a long flight to deal with an ATM on arrival. Only you can decide if you are that type of person. You will pay a little extra for getting the euro in your departure airport, but its not like you will be out $100 on the exchange.

The only reason you might want Euros ahead is because in some airports the luggage carts cost a euro or two in coins, and while the atms are right there where you get your luggage, there is no one who can change your euro twenties for coins.
If you are renting a car, and have multiple suitcases-its a long way from baggage to car rental in most airports.

Italyagain: have you ever been able to get foreign coins from a bank or exchange bureau in the U.S.? In my experience, they were never available -- if I wanted another currency, I paid in dollars to the penny, and got only notes in the other currency. e.g. $121.35 for 100 Euro.

If you will need coins on arrival, take cash dollars and go to an exchange booth in the european airport; you should be able to get coins that way.

Good point-I have actually not gotten cash in the US for Europe in a long time. You used to get able to get a starter kit that has coins. Now I just save a pile from one trip to the next and supply them to friends who are going over.