There is absolutely no need to register UK payg sims in order to use them overseas. They roam out of the box. Both my Virgin and Tmobile UK sims were bought on ebay UK. I put my sim in the Virgin one and it started working (even with data roaming active). Same thing with tmobile. Friend just did the same thing (bought tmobile UK on ebay.uk) a couple of weeks ago before heading to London.

It was mentioned above that CallInEurope will be cheaper to call the US with. I know for a fact that it’s impossible for that to be the case. You can call the US with tmobile for about 4p/min or so. Virgin I believe is 20p. CIE cannot come close to that.

When I'm out on trips, I just buy a cellphone from that certain country I am visiting because usually, it is cheaper than using your own phone which is more likely locked for use in your own country/by your own provider. Or you could try buying unlocked phones over the web. Just a suggestion to everyone, being the Facebook-crazy person that I am, I added two helpful resources about cellphones on Facebook and these are http://www.facebook.com/cellulars and http://www.facebook.com/cheapmobilephones. This could be very helpful, enjoy!

If you're getting a new cell phone, just buy a quad band phone. It will work around the world. You may need to register somehow for overseas calling. This may not be the cheapest answer, but it's the easiest.

Oh, one thing to remember. For recharging a cell phone, you'll need adaptors for UK and continental sockets. See www.kropla.com. We bought a phone in Glasgow and used it on the continent (buying new SIM cards). We needed an adaptor to switch from a UK plug to a two-pronged continental socket.

You could also try companies catering to specific locations. Like, for example in the US there's http://okcalls.com or in the UK there's http://okcalls.co.uk.

I'm grateful for all of the recommendations and information.

As it turned out, my DH got sick and our hotel in Lyon had an old-fashioned telephone room. I just called Orbitz and they changed the tickets. Hotel also had a free computer (with European AND US keyboards) so I was able to keep in touch with London driver that way.

It really sounds like the first phone company to issue a truly international phone is what we all need. How and to whom do we lobby for this?

Att will not unlock a phone unless you have a least 6 months of service with them.According to Best Buy-IPHONES cannot be unlocked for overseas travel. Anyone? I need a new cellphone ASAP!

I ended up buying two unlocked used quadband phones on Ebay for $60 total. Put my old SIMs from 2 1/2 years ago in them and they seem to still work. We will see if I can add minutes when I get to Europe, otherwise I will just get two new SIMs and call it good.

We will be there for three weeks so this is a better option than renting or allowing Verizon to over charge me for air time. Also, if I did use my verizon phone then work could get a hold of me.

I found a nerw web site (I don't know if they're new or I had not heard of them before)...they will give you a local phone number in many many places in the world for a $3 set up and $0.99.month (one would suppose you can cancel at any time)...this number can be programmed to forward calls to any phone all over the world at what appear to be excellent rates.

For example, I've been using my local call forwarding when I visit Britain to forward calls. I pay 30¢/minute to forward to a UK mobile....I was able to buy a local number and the same forwarding costs 12.3¢/minute and it seems to go through very quickly so you can buy such a number and either give that numkber to your friends (after you program it,k easily done on the web) or call forward from the verizon phone....

What's the site, xyz???

This came back after 3 years and the moderators removed newer references to different links. In 2014, I'll be going to Madrid and London--will there be two different phone requirements? Thanks.

In recent years, the EU has passed rules that greatly restrict international roaming charges within the EU. Because of this, it rarely makes sense to buy a new SIM card for each European country you visit. I live in Italy, not Spain or the UK, but I imagine that the situation is much the same in those countries. In Italy, most providers allow you to activate an international roaming plan, free, that allows you to make calls at about the same price as if you were at home. When you get your SIM card in Madrid, tell them you will be using it in the UK and ask if they have any plan to reduce the roaming cost.

You might also start a new question, tagged "Spain" asking about international roaming plans offered by Spanish telecoms.

Thanks, bvlenci.