We use Euros here. The base facilities take both Euro and dollars as well as credit cards. However some places in town only take Euro or Visa. Our current bank account is only a MasterCard. We had to get a new bank account here that had both US and German routing numbers so that we could pay our German bills. Anyhow, that account does have visa card do things may be easier if we don't have Euro on us. We learned this lesson at McDonalds the other day. We ordered our food and tried to pay with our MC. unfortunately they didn't accept MC and we had no Euro on us. We had to leave. It was a bit embarrassing.
Not all places take Visas either but they do take Giro cards. We will have to get a Giro card eventually if we want to travel.
Currently the exchange rate is one USD buys you .73 Euros. Apparently that is low. Eventually it will go up a few more cents and then people will do an exchange so they can get more for their money.
Germany taxes are crazy! I may have posted about this before but I will write again just in case. Tax is 19% here. Instead if tax being added in at the end it is reflected in the actual price advertised. We are able to buy something called a VAT form that will allow us to receive that tax back. It's a nice little tax relief but not every store will accept a VAT form. And this is only available for Americans stationed here.
Excuse any typing errors. My spell check on the phone has a mind of its own and I always dont catch it if it changes it to something different.