How to Get APN Settings on iOS 4.0
- 1). Tap the Safari icon on your iPhone 4.0 to launch the browser.
- 2). Enter "help.benm.at" into the browser address window; then tap "Go."
- 3). Scroll to the bottom of the page and tap the "Tethering" option.
- 4). Tap the "USA" option; then select the APN setting for the service provider you desire to use from the listing on the page.
- 5). Tap the "Download" button. The APN settings will automatically download to your iPhone 4.0.
Source...