From the Apple website, they now list details on what to bring with you to activate your new iPhone 3G. Make sure you have all these items handy to make your transaction smooth.
Snippet:
To purchase and activate iPhone 3G, you need the following:*
- Credit card
- Social security number
- Valid government-issued photo ID
- Current wireless account number and password or PIN (if you’re new to AT&T)
Source Apple Website
