This is part 2 of localizing your iPhone applications. First tutorial use nib (xib) files to localized your iPhone application and this tutorial explain how you can use genstrings to generate Localizable.strings and make your application localized in French language.
Check complete tutorial here.(http://adeem.me/blog/2009/05/10/tutorial-part-2-localizing-your-iphone-application/)
Tutorial (Part 2): Localizing your iPhone application