Public service announcement : turn off your (iPhone) data when you are abroad!

By now you are probably tired of me warning people about the risk of international roaming data on their mobile phone.

But there isn’t a day that goes by without me reading about some poor traveler who went to Farawayistan, turned on his mobile phone and was amazed he was able to get "a signal".

But here is why I’m warning you AGAIN: with the new 3G iPhone (in fact, ANY 3G phone), you won’t only get 5x the speed, you’ll also be on your way to a massive bill 5x faster.

Example: AT&T charge an insane 1.95 cents per kilobyte ($19.50 per Megabyte) when abroad. Since your new shiny 3G iPhone can download on almost any foreign 3G HSDPA network, you’ll reach speeds well over 1 Megabyte per minute, which means you could be charged almost $20 per minute if you have a lot to download. I’m pretty sure most brothels would be jealous of rates like that.

(Image showing 253Mb of data transfer in the UK using an iPhone) 

Once you land, and figure you’ll just turn your phone on "for a few minutes" to see if you missed any calls, or whether you have voicemail, your phone could be downloading all 450 email messages in your inbox. By the time you reach the immigration desk you’ll have run up a $390 roaming bill (20MB of transfers isn’t that much nowadays).

So: turn OFF international data roaming BEFORE you leave the country.

I can’t stress this enough. Even a couple of minutes of major downloading could run up a huge bill. An even safer solution is to ask your operator to disable international data roaming completely, though most operators combine voice and data roaming in one package; you can’t pick just one.

Your phone probably has loads of applications running in the background. You’ve got an RSS reader, an IM Client, the weather, stocks, news and more. Each of those little widgets is downloading stuff in the background. Do you really want to pay $5 to know the weather back home?

One of the biggest problems with international data is that there is no quick way to see your usage. Some foreign operators only send your usage back to your home provider every other month. You’ll get home, and 3 months later they’ll realize you still owe them $4500 (I’m not exaggerating, I know several people who have run into this).

Also, do not take past experiences into account; some people have roamed in the past, and did not get billed, but you may not be as lucky next time. I know some people who got a phone call abroad from their mobile operators credit department asking how they plan to pay their $5000 bill.

If you really need access to data then Wi-Fi is your friend. Check out what a Wi-Fi roaming company like Boingo can do for you. Many current mobile phones can access Wi-Fi, and some (like the Blackberry Curve) can even make phone calls over a wireless network.

Other options include using prepaid sim cards with data enabled, adding a data package to your account (AT&T offer 20MB and 50MB packages with cheaper rates on overages), or simply ignoring email and Youtube for a few weeks and enjoying yourself, like we all used to do when on vacation.

(ATT invoice images from here and here).