Tourists always set aside one or two days for shopping. As I hate shopping, I set aside half a day. I just can't stand crowded stores and crazy customers trying to get the best deals...
Anyway, if you are in Dublin and want to go shopping, you should definetely go to Grafton Street. Located between Trinity College and St Stephen's Green, Grafton Street is the smartest shopping area with many fashionable stores. You also see those souvenirs stores along the street. Go on a shopping spree! Enjoy it!
More info on: http://www.dublintourist.com/directory/shopping/