Last week's expansive leaks (and no shortage of rumor) gave us the opportunity to pick through the hard changes involved in the Apple iPhone HD; a display estimated at 960 x 640, a front-facing camera, talk even of the 1GHz Apple A4 CPU from the iPad. The question remains, though, will the iPhone HD be another game-changer or more of an incremental evolution? Right now, extra pixels and faster CPU aside, it looks more of the latter; the cynic might compare the iPhone HD with OS 4.0 to an ageing athlete, requiring the services of a bolted-on exoskeleton in order to keep up. The new software platform (which has likely saved a few surprises for the official fourth-gen hardware reveal later in the year) brings some much-anticipated features, but they feel a little clunky in their implementation. As I said in my recent iPad review, background notifications and multitasking will work, but they lack the purity found in earlier iterations of the platform.