This should allow you to clear floats in css, without adding extra elements. Add class="clearfix" to elements that need to be cleared. This should work in IE7 as well.

.clearfix:after {
content:".";
display:block;
height:0;
clear:both;
visibility:hidden;
}

.clearfix {display:inline-block;}
/* Hide from IE Mac \*/
.clearfix {display:block;}
/* End hide from IE Mac */

Using various hack management techniques publicized by Doug Bowman and Molly Holzschlag, this is the default stylesheet I to in the head of my markup:

/*
        [CLIENT] screen master
*/
@import url("core.css");

/* Import WinIEx-only bugs - hide from Mac IE5 \*/
@import url("hacks.win.iex.css");
/* END hide from Mac IE5 */

/*       Import Win IE5x hacks
        ---------------------
*/

@media tty {
        i{content:"\";/*" "*/}} @import 'hacks.win.ie5.css'; /*";}
}/* */

/*       Import Mac IE5 hacks
        --------------------
*/

/*\*//*/
@import url("hacks.mac.ie5.css");
/**/

The core.css file contains my pure, "hack free" CSS. The other files referenced above contain any and all browser-specific hackery required to make IElesser browsers behave properly.