I was told I could purchase a disposable phone for use in Europe at the airports. Is that the best place to buy one and can I get one to use in Ireland, Amsterdam and Italy or do I need a different one for each country?
Here is a page which may answer your questions:
http://hop-on.com/pr_042888.html
Here is a page describing the disposable phone in Europe.
http://gizmodo.com/379098/20-disposable-cell-phones-coming-to-europe. Based on what I have read, sounds like one phone will work in all countries.
But an unlocked used tri/quad band phone here and you just buy SIMs in each country or an international SIM for all the countries.
If you get a decent phone here used (I paid about $30) you can use it on future trips. We used it in 2007 in Italy and this year in Ireland.
With a US SIM, you can also use it on the US portion of your trip so you can call from airport w/o having to lug around your US phone.
PM me with any cell phone questions.