YOU NEED TO KNOW that if you're backpacking across Ireland with either Google Earth or Flickr's maps as your guide that neither of those sources provide accurate GIS data. They're both fine for relative information such as point-to-point driving instructions but neither of them align with pocket GPS information that many new cars and backpackers carry. When I used Flickr's new mapping service to automatically import and locate my geotagged images, some of them fell more than 15 miles from where they were shot and cross-checked with our Garmin GPS. Likewise, when I type an exact latitude and longitude for an Irish spot into Google Earth, the same discrepancy unfolds.
This is nothing new to those who know you have to pay to use the Irish geodetic services. Neither Google nor Yahoo do that so your correct location will be more than a few bus stops away on either of their well-used mapping services.