I have a quad band, unlocked, phone card that a SIM card can be used in. I know you can buy a SIM card when you arrive in Ireland but I was thinking about avoiding the hassle and getting a number ahead of time buy buying now while in the States. But several of these online company sites either have reviews stating they are rip offs or are WAY more expensive. Is there anyway to buy from Tesco or Vodaphone etc. BEFORE arriving in Ireland? I haven't found one yet.