@pyroNov 10.2003 — #Put a container div around it all, and use margin: auto; for complaint browsers, and text-align: center; (around the parent of you container tag -- probably the <body> tag) for IE 5.
@bobmurphyNov 12.2003 — #i got a page to centre in both planes ( X&Y) by putting everything in a div and giving the div the following style
div {position:absolute; height:420px; width:770px; top:50%; left:50%; margin:-210px 0px 0px -385px}
those dimensions work for anything from 600*800 up to pretty big - but it goes nuts in version 4 browsers and opera 5.02 - so i used the php function -> preg_match to provide opera with a different style
there are also some pretty good pages on the net that major on centering -- it's worthwhile doing a search