The iPhone and iPad SDK supports reverse geocoding out of the box. Reverse geocoding means you have a coordinate and want to find out where you are located, for instance, the name of the street you are on. 
Forward geocoding means you know the name of a location and want to find the coordinates.  

This API/sample project demonstrate how you can forward geocode using Googles' geocoding service.

Features:
* No dependencies
* Blocks support
* Works with Google Maps V3 API

The source is unlicensed and 100% free for you to use with whatever you want. Read more about BSForwardGeocoding @ http://blog.sallarp.com/ipad-iphone-forward-geocoding-api-google/