Someone just forwarded me an email from the Laughter Lounge which claimed it was open til late on Good Friday - don't know if that qualifies as a club (but I wouldn't think it does). Not much help if your in Carlow though.
A hotel or club can get an authorisation from the District Court to open on Good Friday and sell alcohol. I presume that the clubs I referred to get such a license - surely they wouldn't be breaking the law!?!?