Transformer needed
KS
In order for most US electrical appliance to work correctly in Ireland you will need to buy a transformer - this changes the voltage from 220 (standard in Ireland) to 110, as burkemg said. Some appliances do come with dual voltage switches so it might be worth checking out - however, I have only ever seen this facility / option with regard to stereo equipment
I know Peats in Parnell street used to sell these transformers - when buying a transformer you will need to know the wattage of the appliance to ensure you get a large enough transformer
Also, the transformers can be bulky and ugly, about the size of a large square orange and may look out of place if permanently wired in kitchen (this may not be an issue but I know my better half is fastidious in her quest for clean and un-encumbered lines in a kitchen)
efm