I posted about this recently after an idea from HAP in the States (see her update here).
Just to show I wasn't just posting about it, I did try to follow through on it. Anyway, here's the link to the official site for blood donation in New Zealand. I grabbed the phone number, called and explained my situation (i.e. Irish, visiting and offering to donate – I hadn't been in Asia in over 4 months so didn't expect any problems).
Unfortunately, I got an answer I wasn't expecting as the helpful woman jumped to the final question on her eligibility test, skipping all the others: “Have you lived in the UK or Ireland for more than 6 months between 1980 and 1996?”. Well, of course! And so I was automatically discarded as “there's no official test for Mad Cow Disease.” I was fairly sure we didn't have any outbreaks but she wasn't interested.
Since then, I've been informed from a friend that if I make a stand they will accept Irish as we didn't have any Foot&Mouth problems. Although, I'm now wondering whether they're discount me anyway as I've been in Asia this year. Oh the joys. It's pretty funny, I've been trying to donate again now for over two years with no luck. Everything from having vaccinations for Asia, to having had acupuncture (supposedly still not officially recognised in Ireland!).
I'm moving to Wanaka next week, so will try the local hospital there and see how I go. Will update with new info next week.