I can't get USB tethering to work. My setup: iMac with Mac OS 10.6.2 iPhone 3G, Sofware version 3.1.2 (Build 7D11) The phone shows up in iTunes and syncing works as it should. I went to System Preferences / Network and added the iPhone as a Network Service. To the right there is a status message for the selected service. With the iPhone not plugged in, the status message reads: Either the cable for iPhone is not plugged in or the device is not responding. With the iPhone plugged in, the status message reads: Either the cable for iPhone USB is not plugged in or the device is not responding. Almost identical messages, the only difference is "USB". Any clues?