In order to join your iPhone 2.0+ to your corporate secured wireless network that uses PEAP or other protocol, you have to use the iPhone Enterprise Configuration Tool. It's not possible to configure it from the phone itself apparently. Seems there are two ways to get the configuration profiles onto your iPhone:
- Via the web, by hosting the .mobileconfig file on a network accessible IIS or OSX Server.
- E-mail the config file to your phone.
iPhone Enterprise Config Tool:
iPhone Enterprise Config Tool Deployment Guide: