There are two big controversies brewing in the iPhone world right now, both squarely in AT&T's purview.

The first is that AT&T defaults to sending you detailed information about your phone use, including a printout, arriving through the mail, of every text message you send or receive, as well as every block of data; they do this even if you have unlimited service. The canonical example is a customer whose 300-page phone bill cost AT&T $10 to send.

This is an idiotic waste of paper (blogger Muhammad Saleem estimated it at nearly 75,000 trees per year), but reportedly customers signing up after 10-Aug-07 will instead receive summary bills that basically just say how much you owe. You can also ask AT&T to switch your account to summary billing or to paperless billing, though an email message sent to Muhammad purportedly from an AT&T call center employee claimed that paperless billing would cost $1.99 per month.

But that's not a big deal - AT&T will work it out eventually.

The bigger problem is that, while iPhone data usage is flat-rate in the United States, in every other country it's charged by the byte, and the charges are quite high. Same thing with text messages.

On top of that, many people have their iPhones set to check email automatically every few minutes, something that's not a problem when in the United States, but which generates huge charges when you're in another country.

Consider, for example, that in Canada the charge for outgoing text messages is 50 cents per message, while the data rate is about $1 for every 50K, or $20 per megabyte. Now go to Home > Settings > Usage on the iPhone and multiply your data use, in megabytes, by $20, and contemplate how high your phone bill might be.

There are a few ways you can avoid the high bills that jet-setting iPhone users have been seeing:

• Turn off Mail in Home > Settings, which should reduce the use of EDGE data to nearly zero (just a few packets when you move between EDGE and Wi-Fi). Then, before you check on stock quotes, use Google Maps, watch a video at YouTube, or check the weather, make sure you have a good Wi-Fi connection.
• Remove the SIM card while you're away (see Apple's instructions). You won't be able to make calls or use EDGE, but you will be able to use Wi-Fi. You can even put the iPhone SIM that you just removed into some old AT&T phone, and use that for communicating while you use your iPhone for everything else.
• Put the iPhone into Airplane Mode. That way, you can still listen to music and play video, but you can't make calls or do anything requiring Internet access.
• Call AT&T and sign up for the International Data Global Plan for iPhone, which, for $24.99 per month, provides 20 MB of data usage per month in 29 countries, with overage at half a cent per kilobyte ($1 for 200K) and other countries at the usual $.0195 per kilobyte (about $1 for 50K). A friend was told by AT&T that the International Data Global Plan replaces the domestic data plan, but AT&T's Web site seems to contradict that, so be sure to confirm with AT&T. You do have to sign up for 12 months at a time.