This is my first time using my cell phone with an international SIM card. I have my phone unlocked and am ready to purchase the SIM card. Have been looking at OneSim and GoSim. Has anyone had experience with these companies or recommend another?
You'd probably be just as well-served to pick one up where you're going. You often need one for each country, so it can become a pain in the neck doing it that way.
We are only going to travel in Ireland.
One advantage of buying ahead is that you will know your phone number ahead of your trip, so you can leave it as an emergency number for anyone who would need to contact you.
Then it's easy; do what Nancy said.
I haven't heard of the cards you mentioned, but I have had a relatively good experience (as much as you can with a cell phone company) with O2 Ireland, which worked in England as well.
You can probably buy an O2 sim card online while you are still home. That way you have a card from the country you are traveling to, and you have the # ahead of time - the best of both worlds.
I always use a calling card (bought an international one at Costco) when I call home, though... It's been a couple of years, but I had no problems and it's way cheaper.
This past March we were in Ireland, and purchased and O2 SIM card right there in the Dublin airport, just after coming through customs. I remember it being very affordable (better than deals seen online) and you can buy "top off" minutes all over the cities in markets or drug stores. Also, if you have a wifi phone, O2 lets you sync up easily to free wifi zones. We had booked budget hotels with free wifi, so within minutes of arriving at our hotel we had access to email & the web through our phone. Pretty seamless!