It seems Google has confirmed the notion that Google Mobile uses APIs that are undocumented, opening up the ability to use the built-in proximity sensor in the iPhone for verbal searches. This goes against the iPhone SDK, which states developers can only use APIs that Apple published within the kit.

Google was quick to dismiss more serious claims that they were linking to dynamic frameworks, however. So what’s the big deal about undocumented APIs? Well, whenever Apple updates their software, the application code could break.

Plus, this raises questions about applications accepted into the App Store by Apple. If Apple knew Google was using these APIs and let the application through anyway, it could point to a sort of favoritism. However, Google might just end up rewriting the code if Apple ends up enforcing the SDK terms.