I recently needed to order some printed mugs for a family member in Ireland. Shipping costs from the US were astronomical, so I ended up scouring the net for a place in Ireland that would do what I needed.
Most of the services that advertised as being in Ireland did not work out. While all of the services gave me ways of building the design I wanted, I ultimately needed to customize the photo in a photo editor on my computer and repeatedly upload versions until the print was going to match what I wanted.
Several would not accept payment from the US, including one that let me fill in a US billing address but they gave an error when I submitted the payment. Some required Ireland's postal code for the destination, but didn't like the address when it was filled in (!). Some were going to take a long time to ship the items, whereas I had about eight or nine days to get the item to its destination. Some sites used Flash for the interface, meaning they'll stop working fairly soon as browsers stop supporting it.
In the end photobox.ie was the best option.
The Photobox.ie site itself worked quite well and was the prices were fairly reasonable, it allowed me to buy items from the US and then ship to family in Ireland. The only downside was that the shipping time to Ireland was a little long, ultimately because of the fact that the company was actually based in the UK and items were shipped over. That said, with a little more planning ahead it shouldn't be an issue for future orders.
Will definitely use the site again.