Cross-browser width-dependent clipping

Horizontally-centred layout requires two wrappers (probably BODY and one div are sufficient). WARNING: overflow:hidden carries danger for narrow layouts or large font sizes.
Left-centred layout requires two wrappers (probably BODY and one div are sufficient). Works in Fx>=3.1, Opera, IE8. WARNING: overflow:hidden carries danger for narrow layouts or large font sizes.
Left-centred layout requires two wrappers (probably BODY and one div are sufficient). Works in Fx<=3.0 and IE7 using a floated horizontal prop in place of generated content. To work in IE6 it requires a working combination of width and max-width which I believe can only be achieved through the use of scripting. WARNING: overflow:hidden carries danger for narrow layouts or large font sizes.