My 2nd gen ipod touch runs iOS 4.2 (the current iOS) but they have artificially restricted it so some features don't work on this device. For instance mobile Safari's page search feature isn't present on older iDevices, even though it's running the latest iOS. This feature is there on newer iDevices, but is not present on older iDevices that are running the same exact iOS version. Apple made it so these new features aren't there on older iDevices.