If you try to sync your iPhone or iPod and you get an error like this: "iTunes could not connect to iPhone... because an unknown error occurred," this can sometime be caused by not having enough power over the USB cable. This usually happens if you are trying to sync when plugged into a USB hub, a keyboard, or some other peripheral device that has a USB port on it. If you get this error when plugged into one of those ports, try plugging into a USB port directly on your computer. This will usually fix this error.