Before tossing out your first-generation iPhone for the iPhone 3G we're all anticipating on July 11, you'll need to wipe off personal data, including your passwords and user IDs. CNET's Tom Merritt shows off three paths to iPhone data-cleanliness using iTunes for Mac and Windows. The first method is simple, but will likely leave a swatch of information behind. The second method is for the ultraparanoid with a lot of time on their hands, and the third method averages techniques to get the data coffers mostly spotless. Check it out.