Slovakia's currency became the euro in January 2009. ATMs are available in most tourist destinations. Credit cards accepted in major hotels; with guesthouses, ask ahead.
Slovaks don't tip consistently, but rounding up bills to the nearest euro is common practice.
Restaurants Leaving 10% is increasingly common (and may be expected of foreign tourists). Higher percentages may result in waitstaff assuming you've made an error and following you to return your change.
Taxis Round up the bill by an extra one or two euros.
Pubs and bars Not expected except for table service and elaborate cocktails.