AT&T offers two international roaming plans for iPhones: one at $5.99 per month for discounted voice calling, and another for data usage on EDGE at various price points for different sized blocks of data transfer. I spent January in France and had chosen the 50 MB block at $59.95 per month. When I called to terminate the plans upon my return home, I was advised that it can take up to 90 days for usage (voice as well as data) charges to come though from the international carriers. Unfortunately, the AT&T rate charged to its customers is the rate in effect at the time the charges come through, and NOT the customer rate that was in effect on the date when the charges were incurred. In my case, which I was told is typical, my iPhone showed I had used just under 50 MB of data transfer during the month, but only some 10 MB had been charged through as of the end of the month, leaving some 40 MB of usage which will presumably be charged over as long as the next three months. If I cancel the programs immediately upon my return and stop the clock on the $59.95 per month fee (which can be prorated on a daily basis), then the data charges that come in thereafter will be charged at the non-discounted rate of 2 cents per Kb, which would be some $800 for the remaining 40 MB. To avoid paying this exorbitant rate requires paying $59.95 not just for the one month of overseas usage, but $239.80 for the four-month period over which the charges might be billed! (The same principle also applies to voice calls, but at $5.99 per month to obtain the discount, the costs are an order of magnitude less significant.) The AT&T rep was very helpful and understanding, and agreed that if I paid the $59.95 and $5.99 for only one additional billing cycle, that AT&T would give a one-time adjustment on any subsequent charges up to 50 MB overall. Even though that meant that the cost of using 50 MB over my one-month stay was double what I expected, it is still half of what AT&T could charge had it strictly enforced their Terms and Conditions. If you are thinking about using the iPhone in Europe for a relatively short time--a month or less--the AT&T international roaming plans are not designed for you. They are meant to be in place over a long period of time for people who travel regularly out of the U.S. If you're going to Europe for an isolated trip--even one that lasts for a month--you might find it best to simply turn off the data roaming function (Settings, General, Network, Data Roaming) and plan to use only wi-fi for data. Neither the AT&T website nor the International rep I spoke with when initiating the service mentioned the long tail on charges, even though I made it very clear I was planning to terminate the plans as soon as I returned. I hope posting my experience helps others avoid unexpected charges.