http://gbbf.seetickets.com/tour/great-british-beer-festival-2013
Over 13th and back 15th:
€61 ex Dublin, €62 ex Belfast, €97 ex Cork, €91 ex Knock, but all these prices will drop between now and the middle of June.
http://www.skyscanner.ie/flights/dub/lond/130813/130815/airfares-from-dublin-to-london-in-august-2013.html
August is very far away for me to be thinking of, but I don't hate the idea, I might be up for it!
Went to GBBF last year, and probably built it up too much for myself, but can't say I was impressed at all. For the size of the festival, the majority of beer was very average in my opinion. For various reasons a lot of the well know breweries aren't invited or don't attend. My next trip to the UK for a beer festival will probably be a non Camra one, maybe up North, where the dispense method is not relevant, but the quality of beer is.
I think that GBBF is just too big, so it's very hard to seperate the good from the bad. I've also heard good things about indyman, so might aim for that one.
http://www.indymanbeercon.co.uk/
I went to the Kent Green Hop Beer Fortnight last year and it was good. It was the first one so it should grow better each year.
http://kentgreenhopbeer.com/