Money and Currency
The legal tender in Poland is the Polish złoty (zł, PLN). Poland is expected to adopt the common European currency Euro (€) in ca. 2010 but it can be used to pay in many bigger shops ("hypermarkets") even now. Zlowty is the equivalent to dollars in Poland and grosz is like ‘cents’.
Local banks will exchange money, however with a transaction fee.
Visa and Mastercard are often accepted in stores. Plastic money can be used to pay almost everywhere in the big cities. Popular cards include Visa, Visa Electron, MasterCard and Maestro. AmEx and Diners' Club can be used in a few places (notably the big, business-class hotels) but are not popular and you should not rely on them for any payments. There is an extensive network of cash machines (ATMs).
For the most part, Polish restaurants and bars do not include gratuity in the total of the check, so your server will be pleased if you leave them a tip along with the payment. On average, you should tip 10% of the total bill. If you tip 15% or 20%, you probably should have received excellent service. Also, saying "Dzienkuję" after paying means you do not want any change back, so watch out if you're paying for a 10 zł coffee with a 100 zł bill.