in the system blade under display settings i see black levels,and 3 choices standard,intermediate and extended..what do they do?

you cycle through each and they are suppose to help better match your display's black level. I believe it's only for the vga ouput though, you won't notice a difference from component.

If using a pc monitor with your 360. Use expanded.

They change the black levels with component 480p too. Whoever uses that...

They change the encoding of the color channels sent through the component and VGA ports. Consumer electronics define separate color levels for Red-Green-Blue on a scale of 16-235, reserving the ranges of 0-16 and 235-255 (or thereabouts) for "whiter-than-white" and "blacker-than-black" data. Computer monitors define color on a 0-255 scale. So standard sends color info using CE ranges and expanded sends it using PC-style ranges.

This was done to improve image quality of computer grade monitors that lacked color adjustments and ended up with "washed-out" color. Some folks have found that the enhanced (or intermediate) setting yield richer, better-looking colors (to their eyes) on their displays.

YMMV.