OK, don't want to be giving any ideas to shoplifters here but...
My parent have just returned from their holiday to Arizona (thanks for all the tips guys they have loads of photos of strange rock formations). They hired a car and went up to Utah and Colorado. They bought a shirt in one of the many towns they travelled through. They didn't realise until 700 miles further down the road that the lady in the shop had forgotten to take the security tag off. They brought said shirt home with them anyhow as they couldn't travel back the way they came as they had a flight to catch, but now we don't know how to take it off. We don't have these sorts of tags in Ireland - it has ink in it or something. They've put it in the freezer hoping the ink will harden so they can cut it off without damaging the shirt.

These sound like the tags that Burtons Menswear (and Dorothy Perkins i think). Is it like a square palstic part with ink in and a round 'button' on the otherside? if it is then one of those shops should be able to help you. I would try a couple of shops anyway, even if it isnt exactly the sme tage they use, they may have a tag removing device that fits.

Are they like this? If my dad still has the receipt hopefully a local shop will remove it - even if we didn't buy it there. My mum says the shop assistant who served them seemed a bit distracted...