Why are most HD sources 720? I'm not comparing it to 1080, that's a whole other discussion... What I mean is why isn't it 768? Back in the 4:3 days, 1024x768 was a standard PC screen resolution. This makes sense, 1024 is a round number in binary, and 768 is 3/4 of it. To make it 16:9 widescreen, it becomes 1366x768, which again makes relatively simple mathematical sense. So, HD ready screens are 1366x768... yet HD is mostly 720. Why? Surely it would look better at 768, with 1:1 pixel mapping? Alternatively, wouldn't the TV manufacturers save money by shaving a few pixels off and making 1280x720 screens?