cash, traveler's checks,or charge Ireland

Travelers checks? What are those? Seriously, no one takes them anymore. IF you can find a place to cash them, it will be at highly disadvantageous rates and fees. The easiest, cheapest way to get money in Ireland is to withdraw it from an ATM with your regular old debit card. You can also use your US credit cards there with no problem (as long as you inform your bank/credit card provider that you will be traveling, where and when). If it makes you more comfortable, you could order some euros from your bank in advance of your trip, then use the ATM once you arrive. Check your bank's fees to see what they will charge you for making foreign withdrawals. Some of the bigger banks will charge a lot (per-use fee and 3%), and others, like credit unions, charge as little as 0%. The foreign ATM will not charge you anything - all fees will be charged by your bank. Check your credit cards for their fees, as well. There are some that charge no foreign transaction fee.

You can use Visa and MC just about anywhere, Amex much less commonly. Unless your have a credit card that does not charge a "foreign transaction" fee it is usually better to use cash. When using a credit card you may get asked if you want the charge in dollars or euro. Always say euro to make sure you get the best exchange rate.

We just got back. We used our VISA everywhere, and hardly had any need for cash. (BUT......you will need it for tips!......and for B&B payments)When we did need some cash we went to an ATM and withdrew some Euros using our debit card. For the first time in our EU travels we bought EU $$$ (British Pounds in this case) from our Credit Union. They charged us $8 for any amount we wanted. But we needed a bunch to pay "up front" for our apt rental in London. When we got to Ireland I just went to the ATM to get Euros.