I can only speak from my experience with the touch - the setup may be quite different. But it should be able to access any unsecured wifi easily, and allow you to enter a usr/pswd on any secured. Once it's in there, it will jump wireless points ad nauseam. There may be a setting on the iphone to tell it to 'prefer' wireless over 3G when available. Easiest way to check for wireless is to use maps or youtube apps, I guess it will try to look for them.

However yeah - there may be some proprietary unlocking required, a bonding with a phone service provider before any of that is even enabled.

Maybe jailbreaking is the way to go...