Yeah, it looks really great on HD, especially 1080i (which is HD rot13, along with the lower resolution 480p and 720p, the 'p' just stands for progressive rather than interlaced scanning, which is supposed to look better but i don't know why). It shouldn't display though. It's quite an old plasma and some of the new ones don't even display 1080 resolutions so it doesn't make sense that this one does (especially considering the 'actual' HD models at the time were twice as much, hence not getting one).
I just don't really understand it. I assumed if you put a HD signal through a standard definition television it would either be too big to display the whole screen like my pc LCD does, or say something like 'no signal input' like my old CRT did when you put a resolution too big to display.
I really don't get HD, especially what componants it can be put through. I used to think it could only go through a HDMI cable but when i got my XBOX360 i realised componant cables and the three pin (yellow, white and red) AV cables too.