New tech products are often plagued with software bugs and the like, so it's surprise that there's one with the iPhone 3GS. That said, this is the first one I can remember that actively targets dogs:
You see, it seems that some iPhone 3GS smartphones are emitting a high-frequency tone—something along the lines of 15KHz—that's triggered when the unlock sound, or SMS sound, finish playing.
BGR confirmed this bug with their phone, and other have piped in to say that they too have handsets that have also produced sounds only a dog could hate. Lucky for the pooch, this appears to be software-related, and patch is undoubtedly forthcoming.
Meanwhile, you might have this bug and not even know it, as the tone is apparently to high for some older folks to hear. [BGR]