We will be traveling to Prague, Vienna, Budapest and Krakow. Do any of these cities accept the Euro or will we need to get each countries currency? We begin our trip in Prague. Should we bring foreign currency with us, or just exchange when we are there?
Check the internet for the Eurozone countries. Austria is one, but the Czeck Republic and Hunagry do not yet use the euro.
You can buy euros here (eurocheques through AAA), but it's best and cheapest to use your ATM or debit card when land at an airport to get the local currency. Buy Czeck currency when you land in Prague, then when oyu travel to the next country, use an ATM there. Just be sure your card's PIN is only 4 digits.
Poland still uses its own currency. If you have an ATM card, you can easily get zlotys. ATMs are everywhere. Of course, you will pay a fee.
Oh, the behavior protocol in Poland is to leave a HUGE space between you and the person at the ATM screen. How huge? At least 2, preferably 3 or even 4, people should be able to walk side-by-side between you and the person at the ATM. Don't worry, no one will cut in. So, look carefully for a line - it may be obvious that it is the ATM line :-)
You will find in most of these countries that they will deal in Euros, if you happen to have them, but at their own arbitrary exchange rate. I have had hotels for instance quote me rates in US Dollars and Euros in Prague (and even Marks back in the day). Still best to have local currency.
We just got back from Eastern Europe. Many places quoted prices in Euros even though the country isn't yet on the Euro (Croatia/Hungary). We always use local currency (partially to just be polite) but those that quoted Euros would have taken them. As a matter of fact, they just calculated back into their currency (know in advance what you should be paying). I try to estimate costs fairly closely, but in most cases you can change to another currency after leaving that country. We always bring Euros home with us so we have some when we land next time, but ATMs are usually pretty available at the airports.
Of the four cities, only Vienna is on the Euro; local currency is recommended elsewhere for reasons noted. ATMs are readily available in all cities--Rick Steves' books often provide locations near airports and train stations. (Be alert to who's near you when you use them--we've never had a problem but know of folks who have). Suggest you investigate getting a "pre-loaded" Debit card that is not linked to your checking or savings account back home. If lost or stolen, at worst you're only on the hook for the balance on the card; it requires a 4-digit PIN for ATM use, and works like a regular debit/credit card elsewhere. AAA offers a debit VISA card that charges $2.00/use at international ATMs, but you do have to keep track of the balance (AAA'll cash it out when balance is below $20). Try to judge how much you'll need in each city because it'll cost to convert to the next currency. If you're planning to return, you can bring Euros home to start the next trip.