Using the iPhone with ATT outside of the U.S.
1) ATT has a new $24.95/month supplemental international iPhone plan (over and above your normal iPhone plan) that includes favorable rates for international phone (similar to ATT World Traveler) roaming plus 20 Mb of data (on a monthly basis). Data charges above 20 Mb are about $.02/kb. This plan is only available on a one year contract basis.
2) The above is a bit pricey so one can activate ATT World Traveler ($5.99/month) for intenational roaming and get that $1.29/min. rate for France down to $0.99/min. World Traveler can be started and stopped only for trips and is a non-contract add on.
3) To make international calls from the U.S. ATT WorldConnect at $3.99 per month is a pretty good deal. the savings can be dramatic and can offer as much as a 10X reduction in rates. Remember you will still eat up your minutes unless you're calling on the nights or weekends. The WorldConnect rate for France is $0.09/min. to a landline phone there.
4) No matter which plan you'll use your phone account needs to be "validated" for international operation. They have a group that does this and it takes about 10 minutes. It involves mostly a series of questions to verify that it is really you who is requesting international service (a fraud protection). Do not assume that you can just take your phone to Europe, or anywhere else outside the U.S. for that matter, and begin using your phone. Get it "validated" first.
5) In my case, the $24.95/month for a year is not worth it as I travel to Europe only 3-4 times per year. I have elected to get ATT WorldConnect at $3.99/month as I do make calls to Europe. I will activate ATT World Traveler about a week before I travel and stop it when I return (for international roaming). SMS messaging will be billed at $0.50/message outgoing and free incoming (since my iPhone plan has 200 messages). Above 200 I will pay $0.15/message incoming. Data will be billed simply at about $0.02/Kb so the order of the day will simply be email with only the first couple of lines downloaded unless i reaaly have a message I must respond to or read in detail. My normal trips to Europe (2 weeks) will eat up about $15-$20 in email data charges (this was on T-Mobile which is similar to ATT in this regard).
When I go to "My Account" on the ATT web site I see under "Rate Plan and Features" and then "Added Features":
AT&TWldConnect $3.99 (International calling plan from the U.S.)
EXPANDEDINTLROAM $0.00 (International validation)
Mini + iPhone Mac OS X (10.4.10)