iPhone--Should I buy one in the US before we move?

Planning to get mobile service in London.  I have no idea what carrier I'll go with.  Other than T-Mobile I'm not familiar with the mobile companies over there.  I'd like to get an iPhone.  I'm guessing they're a whole lot cheaper here in the US than they are there.  Would I be wise to buy one here before I leave?  I'm assuming an iPhone purchased here would work fine over there.  Or would there be some kind of new customer promotion if I buy the iPhone there in combination with a service contract that would be to my advantage?  Can anyone tell me how much an iPhone over there will set me back?  Thanks!

an iphone locked to at&t would not be a good idea, as you won't be able to use a UK sim card and will incur loads of roaming charges if you used your AT&T plan.  An unlocked iphone would be okay provided you can find a UK sim that would work with it. 

But- if you're not averse to a contract, it's much easier just to buy the iphone over here. the prices on contract  are actually comparable to US prices (for the new iPhone 3G, anyway) so there's not a huge financial advantage to buying in the US in this case.  If you have trouble getting a contract though there's a Pay as you go version of the iphone coming out on O2 later this year.

I'm currently using my US purchased iphone in the UK on a pay-as-you-go sim card from O2.  This required me to unlock the phone from ATT first, then change the phone settings to UK so phone numbers would display in the proper UK format.  Not too difficult to accomplish all this, but certainly not for the faint of heart.  The only way you are going to be able to use your US purchased iphone in the UK is to unlock it from ATT.  Otherwise, as the previous poster said, you'll have to pay outrageous roaming charges to ATT.   
My husband went ahead and bought the iphone here in the UK.  The iphone was free under a 18 month contract for £45 per month with O2.  Under less expensive monthly tariffs, the phone costs £99.  Much cheaper than what I paid for the phone when it was first released in the US.

Sounds like I'm better off waiting.  Thanks for the replies.  45 pounds a month is a lot!  (How do you get the pound symbol on a US keyboard?)  I hope I can find a cheaper contract.  Why would one have trouble getting a mobile phone contract? 

A week from today we'll be on the plane to London--one-way tickets!

My Husband has the new iPhone which I paid £99 for (Father's day present) and he has a £30 contract with that.  (That is the cheapest contract you can get with the iPhone, I believe)

You might have trouble getting a contract with no credit in the UK.  Even after a year (I've been here five now) my husband still had to take the contract out for me.  Before that I had Pay as you go.

Thought I would add...I have a UK Motorola Razr that was unlocked from Orange so I could use it here on my AT&T. I've encountered problems with it dropping my calls and other various things...and AT&T can't help because the phone wasn't purchased through them and therefore isn't under their warranty.

D'oh!

But it looks like you've made your decision, hehe. Good thing now is that I can at least use the phone still when I move permanently to the UK in a couple weeks and just get a sim for pay as you go.

 crazycrabbe,How did you get AT&T to unlock your phone? Im moving to the UK and they want do it for me.

Once you unlock the iphone from att, can you use it again with your regular att sim card when you are back in the us?

British phones are so much better. Theres one that has 8 megapixel. In USA, they don't even sell N95's. British phones also work better around the world. American phones tend to be restricted because of the frequency they use.

You can only unlock a 2G iPhone as of now.  You can soft-hack a 3G iPhone, but that only allows you to add software on it which may not be from the Appstore, not use a different carrier.  To do that you can go to jailbreakme.com I think.  If you want to use your phone on different networks, you'll have to hard hack it.  Unless you're on the PAYG phone plan (which I think they may have gotten rid of) you'll have to pay an early termination fee, which I guess you'd have to pay if you're moving to the UK anyway. 

I'm not sure why ATT is offering to hack someone's phone because it dfinietely violates their agreement with Apple.  I wouldn't trust them.  It's probably best to unlock (hack) your own phone because when software updates come out, you'll be able to easily update your phone with the hacked update (usually comes out 3-5 days after Apple releases the update).  I believe the best software for hacking a 2G iPhone is called pwned and you'll have to download it from the internet.  It's available from http://blog.iphone-dev.org/, but just know you have to download it from a torrent site, though it is free.  DH recently discovered that if he pays an extra £10/mo he gets unlimited data on O2 and so it only costs him £20/mo or so.  You can find already hacked phones on ebay, but they're pricey.

I think there is a way to use it again in the States, but when DH and I went back to California recently we had issues with getting his phone to use a PAYG Att sim card.

Just remember that purchasing a 3G iPhone forces you into a contract, though I think it's only 18 months in the UK instead of 24 in the UK, but the tariffs are quite high.

I'm not sure what type of computer you have, but I have a Mac and I can type pound by hitting option+3. 

You can only unlock a 2G iPhone as of now.  You can soft-hack a 3G iPhone, but that only allows you to add software on it which may not be from the Appstore, not use a different carrier.  To do that you can go to jailbreakme.com I think.  If you want to use your phone on different networks, you'll have to hard hack it.  Unless you're on the PAYG phone plan (which I think they may have gotten rid of) you'll have to pay an early termination fee, which I guess you'd have to pay if you're moving to the UK anyway. 

Actually, I am not sure that is true. I don't know what this does in terms of your phone, but I believe you don't have to pay termination fees on a contract if you're moving somewhere where service is unavailable, except for roaming, and I think UK applies. However, since the phone is subsidised, I'm not certain what they'd require you to do with it, return it maybe?

ETA: http://forums.macrumors.com/showthread.php?t=366521a year out of date, but at least a starting point.

ETA2: Not really germaine but for two years now I've been wondering what the big deal is about the iphone and then I got to play with one last week and...WANT!

Actually, I am not sure that is true. I don't know what this does in terms of your phone, but I believe you don't have to pay termination fees on a contract if you're moving somewhere where service is unavailable, except for roaming, and I think UK applies. However, since the phone is subsidised, I'm not certain what they'd require you to do with it, return it maybe?

Ah!  Good point!  I had forgotten about that.  Sorry, wrote that post right after waking up

And you're not the only one I know who gets sucked in to the power of the iPhone.  I worked for Apple until May and when the iPhone came out Apple gave all their full time employees a free phone.  My friends would be bashing it and then I show them what my phone could do and they'd freak out and want one immediately.  The new software has even more bells and whistles and obviously this was before the App store even came out.

The thread which is linked is incorrect regarding changing carriers (right about the early termination fee though).  All US iPhones' software is locked to Att, it has nothing to do with the sim card.  Merely putting an O2 sim card in won't work.  This makes it more difficult for people to go over to the US and purchase a whole bunch of phones to sell in other countries where the phone might be much more expensive or non-existent.  You have to actually wipe the software from the phone and put new software on which is almost exactly the same, but will allow any carrier to be used.

It was the Nintendo NES emulator that got me.

I'm sorry to bump this old thread but we're thinking of buying an iphone for mr mort but were wondering if it would work with a different sim card in the U.S? We were thinking of getting the paygo plan from O2 and getting it unlocked. Anyone have any experience with either using the UK 3G abroad with a different sim, or using it with a different UK carrier?

Thanks in advance!

I'm not sure what type of computer you have, but I have a Mac and I can type pound by hitting option+3. 

That is good to know, thanks Cleo!