I thought the data plan was required, which seemed a little excessive considering every other AT&T smartphone can be had without data. However, the current iPhone 3G page doesn't appear to stipulate that data is required. Link to AT&T iPhone 3G page First, the page reads as though you can add a data plan. Second, the page shows the prices as 16GB $299* and 8GB $199*. The asterisk reads, Finally, the Press Release (PDF) states similar optional language regarding a data plan.