I have benefited from the Bank of America alliance with my Canadian bank when travelling in the States, but as per your question pertaining to Ireland, I don't remember seeing Barclays in the Republic of Ireland. However, if your travels take you up to Northern Ireland (UK), your withdrawals should be fee free there using Barclays. I know that is little consolation but I'm just putting it out there in case anyone may benefit from that info.
I had a little chuckle reading ShopAround's message. When I landed in Milan in March, I was searching all over the place for the Deutsche Banks so I could avail of the fee-free banking. I found a bank, tried my bank card and found out to my amazement that it would not work at all. I found another Deutsche Bank and the same thing happened. I was disappointed to find out that I would have to go to other banks and get charged for my transactions. Upon seeing today's thread, I'm kind of glad to know that I would have been charged regardless, but my advantage was that I knew I was getting charged, unlike ShopAround. I feel for ya, SA!