rounded corners only work in firefox (unless you use images for the corners, which you can't do with stock myspace tables)....
table table table {
background-color: 666666;
-moz-opacity:.50;opacity:.50;
-moz-border-radius: 10px;
border: 1px solid 000000;
padding: 10px;}
table table table table {
-moz-opacity:1;opacity:1;
-moz-border-radius: 0px;
border: 0px;
padding: 0px;}
and the opacity will affect all the content too....