iPhone Activation for Dummies

iActivator is a nice Mac OS X application which allows activating your iPhone without a contract. It provides a nice graphical user interface and is very well suited for the non-technical people.

You can easily do with the UI the all manual steps involved - Jailbreak (setting your iPhone in a state where it can be written to), writing a pem file (certificate file) which allows for activation, generating a plist file which is used for activation and the activating your iPhone with the plist file.

Activating the iPhone will allow you to access all of its functions, including browsing, except making a phone call. Think of it as a souped up iPod with less memory. It is also useful when you are using the iPhone only for development or testing purposes.

Link with instructions here.

It also allows you to deactivate and return the iPhone to the original state.