Ireland created a very strong local tech industry by offering large tax breaks and grants for tech companies - with the help of the EU. This is why places like Dell and IBM (or HP? Big tech companies either way) have massive installations in Ireland.
Now that the EU is expanding, a lot of these companies are eyeing off places like Poland.
I don't know how much these things vary within the EU, but from my own experience coming to Austria, as long as you can find a job in which you earn more than ~34k Eur/year (a bit less that 50k Usd/ year - not very difficult at all to do as a programmer) and have at least a bachelors degree (better a masters), getting a work permit is not that difficult.
Actually, just recently a new visa scheme has been announced that would allow people from the US to travel to Ireland and Irish people to travel to the US to work for a year. I'm not sure when it will be available but it seems interesting. The Irish Times did an article on it http://www.irishtimes.com/newspaper/ireland/2008/0919/122177...
Now that the EU is expanding, a lot of these companies are eyeing off places like Poland.