Three have by far the best deals
I am actually in the EXACT position as the original poster, mcfly.
I have a Verizon iPhone 5 that I purchased mainly because I'd never had an iPhone (but had been a Mac user since 2002), and the fact that it was unlocked for GSM out-of-box. I'm going to the UK for two weeks in March and needed some good inexpensive prepaid voice and data access.
I did decide to go with Three, especially after seeing their deals for prepaid:
http://www.three.co.uk/Store/SIM/Pay_As_You_Go [make sure you get a nano SIM!] They offer 300 minutes, 5000 texts, and all-you-can-eat data ("unlimited", no fair use policy or MB ceiling to hit) - all for £15, or $24.
I also got a second one from giffgaff, which uses the O2 network [
http://giffgaff.com/goodybags] and may get the £12 (250 minutes, unlimited text and web - though web is reportedly not truly unlimited) if Three doesn't have good coverage.
Neither site offers US delivery of SIM cards (and giffgaff doesn't even offer nano SIMs!) So off to eBay I went! I got them both for less than $10 bucks overall - make sure if you buy a
Three SIM that it's genuine, since they actually produce them for the iPhone 5. The
guy who sold me the giffgaff one cut it down and tested it, and even sent me overseas visitor instructions by mail and online.
I was able to activate the Three sim card by popping out the Verizon SIM and registering my number (printed on the packaging) on their site. You can't use a US credit card to top up, but you can buy a voucher through a
third party, that will send it to you by email, so you can have service when you arrive!
Three really is the best though. You can have your family in the States text you at a Google voice number as a "signal", and then you can call them for only 3 pence a minute, with
this deal. Or they can get a calling card and call you (it won't cost to receive - they will just need a way to pay to call you, i.e. a calling card)
Just make sure you top up before you leave for your flight, switch cards before you leave the plane, and you're good! Hope this helps!
Does anyone have experience with giffgaff? Anything to be said there?
Also, not sure if anyone would know this, but do any of the carriers majorly limit your plan in particular ways? Specifically, I'm wondering if I would get an unlimited data plan, would I have to pay extra or be blocked from using Skype over that data?
Thanks again.
Skype is part of Three's data plan, as is Facetime!
I know a lot of the providers are shying away from truly unlimited data - Three is the only provider that really offers it.