To customize the layout of your WSS search results page you just need to edit the file searchresults.aspx located in
C:\Programme\Gemeinsame Dateien\Microsoft Shared\web server extensions\12\TEMPLATE\LAYOUTS
or
C:\Program Files\Common Files\Microsoft Shared\web server extensions\12\TEMPLATE\LAYOUTS

Look for the SearchWC:CoreResultsWebPart tag and add the attribute OnPreRender="PreRender_Handler"
On the top of the page add the following code-snipped:
<script type="text/javascript">mce:0</script>

I used this to add a link to the results parent folder. Unfortunately you have to handle this with regular expressions.
Perhaps there is a better way, but I did not find any.