Apple has updated the Find My iPhone app so that it better handles your offline devices. Find My iPhone can locate, send messages to, and play sounds on your iPad, iPhone, and iPod touch--but apparently Apple prefers the app's current name to "Find My Miscellaneous iOS Device."
In the past, if you attempted to use the app to find devices that were currently either powered off or offline, the process would fail. Starting with Find My iPhone 1.2, the utility will keep looking for your devices if they appear to be offline when you first try to find them, and shoot you an e-mail if the device you're searching for comes back online and is located successfully.
Also new in 1.2 is the ability to remove offline devices from Find My iPhone's saved list, within the app itself. That way, if you've decided you're simply never going to find that missing-in-action iPod touch--or you have iOS devices whose whereabouts you no longer care about-- you can tell Find My iPhone to stop tracking them.
Find My iPhone remains free, and requires iOS 3.1.3 or later.