Can you purchase a prepaid cell phone to use in Britain that will call the US? if so, are they sold at London's Heathrow and how much do they cost?
Here is the usual rec for Pay As You Go (PAYG) phones in the UK. Carphone Warehouse which sells cheap unlocked handsets (from about £15 including £10 call time) and SIMS. You choose your calling plan based on your needs, discuss with the store assistant. (BTW bought a new handset from them yesterday, very helpful service). You won't find them at Heathrow but seemingly everywhere else!
http://www.carphonewarehouse.com/mobiles/pay-as-you-go/deal-finder?&dealType=PPAY&phonePrice=0:1000#
http://www.carphonewarehouse.com/mobiles/sim-cards/sim-card-tariffs
Ask about plans which include international calls, usually very good value. Remember we pay nothing for incoming calls/texts over here.
PS - at first glance (have not read the small print!) the "Talk Mobile" International SIM looks like a good deal.
If you specifically want to buy one at Heathrow (I found myself in the same situation!) and don't want to (or don't have time to) buy an unlocked phone in the US first, you can buy a prepaid phone at Heathrow. If you can get to a Carphone Warehouse, that is the best option for buying in the UK.
Someone (I think it was Linda) mentioned in another thread that you can buy many prepaid phones at Heathrow, but the cheapest pay-as-you-go phones are locked to their UK carrier (unless you buy them from Carphone Warehouse or another third party.) You can still call internationally pretty cheaply from them, but you may have to ask the provider to turn on this feature for you.
I emailed Vodafone, since they have a big store in Heathrow Terminal 5, and they said that they sell prepaid phones there. Vodafone does also have a feature that will let you make calls from other European countries for a surcharge per call. You might even be able to buy a Vodafone SIM in another country if the phone is locked to Vodafone, but you'll have to ask.
Just sharing my research :-).
Thanks Steve! I went on Ebay and found one for $29.95 with free shipping but since I waited until the last minute like a knucklehead, I had to pay another $29 for overnight shipping. I'll buy the SIM card at Heathrow. Linda and Lexey also had great advice. Thanks everyone!
Lexey - "Someone (I think it was Linda) mentioned in another thread that you can buy many prepaid phones at Heathrow"
Not guilty your Honour!!! Always rec an independent retailer.
Sorry, Linda! I read somewhere that the cheapest prepaid phones are locked to a carrier if you buy them from a specific phone company's outlet or at the airport--I was just trying to pass on that advice if someone really needed to buy a phone at the airport and thought it might be unlocked to use with any SIM card. I couldn't remember who passed on that advice to me. My apologies :-).
There are Carphone warehouses everywhere. I bough a £15 phone with a £10 top up. I could call the US if I chose for 5p a minute anf could text for 10p. I though 5p was quite reasonable. My phone was on Vodafone and the phone is a Nokia.
There is no CarPhone Warehouse at Heathrow, though, alas, so if that is your only shopping option because of your itinerary, like it is with mine, you are stuck with what is on offer there or trying to buy a phone in advance so that only a SIM card is needed. Like Tom and Steve, I bought an unlocked phone in the US and plan to buy a SIM at Heathrow, so buying a phone in advance is helpful advice if time allows.
What I found out somewhere (!) is that you can buy a prepaid phone at Heathrow, but if you buy the cheapest ones, they are locked to the carrier that sells them, which might be an acceptable trade off to some since all of the UK and European carriers give better rates than any of the international SIM cards you can purchase from the US for services like Mobal or Telestial (although Telestial is far better than Mobal costwise). I found that to be useful information, and bought a phone in advance.
HOWEVER, if you are able to buy an inexpensive phone from a third-party retailer, it is not locked to a specific carrier, so going to the aforementioned Carphone Warehouse is a great idea if you can do it. I found, though, that although CarPhone Warehouse is seemingly everywhere, there is not one in Orkney, which is where I am going from Heathrow.
My response to the original poster was an attempt to help with the specific question of buying a phone at Heathrow, which was the same problem I was faced with. I guess my other response was not clear. I hope that if someone else has this specific question about buying a phone at Heathrow in the future, they may find this explanation of that and of the alternatives offered by several here helpful.