Thanks for the replies. Indeed, I think the selection of Irish beers in the local sports bar where I am going is better than in a lot of places at home, but still and all you can't beat real stuff from home (or so I'm told). This is of course despite the fact that the stuff consumed here is probably brewed in a mega-factory in Birmingham or Shanghai or something.
It's only supposed to be a small token carried over by me, so I don't think Fedex would meet the criteria.
I was thinking of getting it in Duty Free, but have heard bad stories of stuff being confiscated before getting on the internal US flight. Because you can't transit directly after arriving on an international flight you have to go back through the 'normal' domestic security that everyone else does in the US so you fall foul of the usual carry-on limits again.
I might bring along a small suitcase just for the purpose - there isn't the same strict luggage quantity restrictions on trans-atlantic flights, so that should be OK.
Cheers,
z