be careful if you're condsidering buying one cause many that are marked as HD-ready are not...
to be truely high definition it must have a HDMI (hi def multimedia interface)
http://news.bbc.co.uk/1/hi/technology/4361543.stmwith regards to films...they will have to have been shot on hi def cameras which means the picture has at least 4 times and many pixels to display what has been recorded and thus the sharper image
one thing i've never understood...why bother showing ads for hi def tv on non hi def tv's...you wouldn't notice any difference