You probably could have gotten AT&T to unlock it. I had the same issue when going up to Montreal recently, and I just emailed them and they unlocked it for me without a hassle.
If just traveling to the UK, pick up a SIM from 3 (http://three.co.uk). They offer prepaid unlimited data for 30 days for £15. You can either get one for free (or cheap) in a 3 store, or they actually have them in vending machines at Heathrow for £10. If you buy in a store they can help you finish up, purchasing credit, etc. If you went with the vending machine route, then you just need to go to a convenience store - or even most ATMs - and buy credit. You can do the rest of the setup over the phone. I did this the last time I visited the UK and was set up before I got outside of the train station in central London.
For France, .... not so easy. They're really unwilling to help you set up a SIM if you're only going to be there for a short period of time, which is almost reasonable as the SIM activation period will probably last a few days, so you might not be able to use it.
Everything in Japan is easier - from the trains to wireless service...it just works and works well with no bullshit. It's easy to forget that the rest of the world hasn't caught up.
The one country I still have trouble getting reliable data service in is Canada. Rogers offers a pay-as-you-go plan but it's pricey, spotty and only 2G EDGE speeds (with unlocked US T-Mobile handset). And it's a monthly plan too so it's basically use it or lose it as the balance will be eaten away in between visits. I can't even reload it over the web as they only accept CCs with Canadian addresses. Still, it beats $400 in roaming charges!
I second the b-mobile recommendation. I use them every time I go to Japan with a little portable wifi hotspot - a 1 GB data sim for $30 instead of paying $30/MB for Docomo! And they sell them in all form factors.
In addition, if you manage to run the SIM down out of data, you can just refresh it online with credit card - it will let you communicate to the website where you can pay another $30 for another 1 GB.
~$3/day (for me) is a godsend for having maps, nav (including train connections!), and search working wherever you go. I used to have to carry a big 800 page (already out of date) travel book in my pack.
I strongly second the rec for Three. They also sell pre-loaded data SIMs with 12Gb (expiring after 12 months) for £70. (This may be more use than "unmetered" -- in practice probably capped at 1-2 Gb -- expiring after 30 days if you're in the UK for any length of time.)
A new wriggle is that from July 2014, all EU cellcos will be required (by an EU directive) to charge international roaming -- including data -- at domestic rates. So if you buy and activate a pre-paid SIM in the UK and get the cellco to unbar international roaming it should work fine in France and elsewhere. (The devil, of course, lies in the contract details, so we'll have to wait and see how this is implemented.)
6.1: Their security policies look dangerous to me. I bought a pocket wifi device for my mother to use at her home. It came with a sticker explaining the unique SSID and password. The manual said to put the sticker inside the case of the device but I wasn't concerned about physical security so I put it on the outside.
b-mobile worked great for me a few years ago in Japan (I had to find the SIM card at a Bic Camera shop myself - Narita/hotel delivery is definitely an awesome improvement) and I'm glad to hear they're doing well. A few years out of date (2010) but I did a writeup of getting mobile data around the world when I was doing some traveling. Japan was actually one of the tougher ones (Softbank SIMs were charging at $31/MB w/ no cap for data!): http://randomfoo.net/2010/07/19/mobile-data-while-traveling
For those looking for a comprehensive resource, the there's a Pay as You Go Sim with Data Wiki that's pretty well maintained. I've found that data in Europe is usually ridiculously cheap (oftentimes 500MB or 1GB is given away w/ the SIM) and these days I tether with my Android handset w/o problems (and always have a spare battery/charger handy).
Looks like Orange currently sells data-only SIMs for €10/GB in France, and as mentioned 3Mobile has a month of unlimited data for £15 in the UK. I picked up an Orange SIM in Spain and an O2 SIM in Germany recently (which came w/ 500MB of data free) and had no problems getting things running in minutes.
A 22-hour turnaround time for customer service, especially when you email on a Sunday morning, is slow?
I was in Japan and rented a MiFi hotspot for 10 days. Best $100 spent. Unlimited internet, usually about 4 mBit. Worked on the trains and I could make calls through my laptop.
The company delivered the hotspot to me at the Narita Airport Post Office with a self address envelope for me to drop it off when I was done.
If on of your target markets is people visiting the country for short periods of time then 22 hrs could be a substantial portion of time.
I've had the opposite experience. When I went to London a few years ago I bought a sim card at a vending machine at the airport with a few GB of data. I could add more over the phone if needed. I went to Japan last year and spent a day going to different shops in Tokyo trying to get a sim. All of the stores required long-term contracts and a Japanese home address (I had a similar problem trying to use a cyber cafe since I went without Internet on the trip).
In talking to other tourists, it turns out that it's way easier to pre-order a sim online and have it shipped to your hotel. The converse seems to be true for London. That info was kind of hard to find online at the time.
I was looking into options for visiting the US and one of the services looked reasonable so i decided to see where the closest location to pick one up was: 300 miles away from where I will be staying. I am probably going to go with add-on roaming package or a canadian firm that does sim cards specifically for visiting the US.
Hey Tribune- I run a company that does local and roaming SIM cards, focussing on mobile data access. Happy to help with a local US or Canadian SIM...not sure if I'm meant to post a link so I won't, but shoot me an email and I'll send through the details..
I recommend GiffGaff for the UK & http://blackwireless.com/ for when travelling to the US
Hey Mike- you are right, Canada is far from perfect when it comes to getting a prepaid SIM that offers good value, coverage and is easy to activate/recharge before you get there... I run a company (datago) dealing in local and roaming SIMs... The best I could find for Canada was the Virgin Mobile SIM, which ticks most of the boxes, but you still have to find a place to buy a recharge voucher once you land (actually not too hard...but a bit unnecessary in an ideal world). Happy to help for your next trip, or keen to hear any ideas you might have! cheers Pete
Using lhl's wiki link above, I just ordered a 1gb prepaid sim from Similicious for my trip to Toronto next month. Seems to be what I've been looking for - talk and data for $55 CAD without monthly charges or contract and they mail it to me direct. Hopefully the speed and coverage is decent.
In June, we were in Greece for two weeks and Austria for one.
WIND in Greece was ~ $12 for 2GB for a month, and worked perfectly.
Orange in Austria was ~$13 for 3GB for a month, and also worked pretty flawlessly, but with one hiccup I wanted to pass on to travelers.
Orange required a credit card to get the SIM. (WIND required registration, but was fine with cash)
What I had forgotten from the last time I activated 3G with AT&T back home was that it auto renews. It's rather difficult to cancel the auto renewal when you're back home and don't have access to the Orange network on your iPad.
I wouldn't have even know except that I saw the charge and then received an email, in German, from Orange and ran it through Google Translate.
They required the sim card number to cancel the auto renewal, so it was lucky I had kept mine as a souvenir. If I hadn't, I would have just had to put a stop on the credit card. As it was, they successfully got an extra month's fees.
So Pro tip: If you're getting 3G service in another country, don't forget to cancel it before you leave that country. Also, hang on to the paperwork and the card the sim was punched from.
If traveling to Japan I can strongly recommend Global Advanced Communications (http://www.globaladvancedcomm.com/), especially if you want voice/SMS in addition to data. You can pick it up and drop it off at the airport or have it shipped to your hotel.