April 30, 2011
Here I present some thoughts and advice resulting from my traveling recently to 4 countries in Europe.
First of all remember that your carrier may offer special deals for mobile Internet access while traveling to Europe, but the reality is that nothing can beat buying a local prepaid (or “pay as you go” as Brits say) SIM card and putting it into your iPhone (remember it must be SIM-unlocked so if it is carrier-locked it must be jailbroken and unlocked with ultrasn0w).
However if you insist on using your home carrier in Europe, you may encounter problems like, which network to choose? (here: French networks):

… and even if you decide, the network may become unavailable (if you are moving):

Another problem is that Europe consists of several countries, some of them rather small and you can encounter networks from neighbor countries together with local ones (here: French and Belgian networks all available for logging in):

… carriers do some tricks with power so that phones “accidentally” log-in to foreign networks in border area. So if you use e.g. prepaid SIM bought in France but you are in area close to Belgium: be careful on what network you actually are logged into.
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However all in all the best way is to purchase local pre-paid SIM card in given European country (one per country) but it may be tricky to set APN = access point name:

… as often this info is not included in the package and you have to browse Internet to find it, but you don’t have Internet access because for that you need that SIM card and a vicious circle ensues. So the best way is to prepare and have list of APN settings for all prepaid SIM cards with you before you go to leave home!
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Here I would like to once again underline that thinking the meager amount that your home carrier offers for international traveling will be enough for you is WRONG. Here are some reasons why it is good to have prepaid SIM card for mobile Internet while you are abroad:
* you can use Google Maps to find directions, but Google Maps offers also information about points of interest nearby – very fast pool of information not available in other apps.
* you can check-in to Foursquare including photo uploading (see my example here)
* uploading photos to Twitpic, Flickr, etc
* tweeting
* voice over IP over 3G – not only Skype but several other apps available for that
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There is quite new EU-wide law that international data roaming inside of EU should be cheap, and in fact prices for such roaming has been reduced, but this law doesn’t apply to prepaid SIM cards, so don’t think that you will be able to buy Spanish card and travel to Portugal with it, but remember: buy one good prepaid SIM card for mobile internet per one country!
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It is worth mentioning that some European SIM cards work across several countries without additional charges for Internet. For example one can buy a SIM card from “3″ operator in Austria (also available outside of Austria) which has 1 GB traffic per month usable not only in Austria but also in all countries where “3″ is operational (it includes UK!).
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Conclusion: if you travel to Europe you should pick local SIM card in prepaid form but first you should prepare a bit and be careful to use it wisely as described above.
