AT&T unveiled two new iPhone-exclusive data plans today for international usage:
$119.99 / month for 100MB of data
$199.99 / month for 200MB of data
While no long-term commitments are required, one month is the minimum purchase period (i.e. you won't be able to get 2 weeks pro-rated). Also the pricing is in addition to, not instead of, your regular service plan, which would make for one hefty bill.
Executive VP at AT&T, Bill Hauge, said, "AT&T has worked diligently to provide affordable options for international roaming because the feature-rich mobile experience of iPhone is indispensable to users." On a pay-per-use data plan users could expect to pay as much as 2 cents per kilobyte, translating into nearly $40 for a mere 2MB of data. Using this rationale, AT&T appears to think that hitting you with a bill for nearly $300 is a steal.
On top of that, the plan only covers 67 countries, charging additional fees (varying from 1-2 cents) for international usage outside of these areas.
