Did some digging from MS Hotmail inbox, which has the feature I wanted, and found the solution. I have tested this with IE 6 and Netscape 6 and both work fine, but if I remember corectly older versions of netscape have difficulty working with "div" tags.
First the head section style sheet with the color you would like the backgroung to be:
<style type="text/css">
TR.H {BACKGROUND-COLOR: #F3F2EB}
</style>
Then You put in the function. I have it set so that when you click another data tag it is the only one highlighted, and when you click a highlighted cell again it de-highlights. To have it keep highlighting just take out the entire "if" statement and put in "lol.className = "H"".
<script language="Javascript">
Starter = false;
function doStuff(lol){
while(lol.tagName!="TR"

{
lol=lol.parentNode;
}
if(Starter == false){
Starter = true;
GlobalObj = lol;
GlobalObj.className = "H";
}else if(lol.className == "H"

{
lol.className = "";
}else{
GlobalObj.className = "";
GlobalObj = lol;
GlobalObj.className = "H";
}
}
</script>
Then you simple wrap your the CONTENTS of your table data tag in a "div" tag. I have used the onclick event, but you can use ondblClick and onmouseOver events as well.
<table>
<tr>
<td>
<div onclick="javascript:doStuff(this);">
Click TD One To Highlight!
</div>
</td>
</tr>
<tr>
<td>
<div onclick="javascript:doStuff(this);">
Click TD Two To Highlight!
</div>
</td>
</tr>
</table>
Let me know if you have any problems or would like it customized.
kibboy