Give a page a transparent look.

This is very simple to do, but looks best using iframes.
*( Iframes are for internet explorer only )
For every page you want transparency to take effect
simply the following in the head section

<style type="text/css"> BODY { FILTER: alpha(opacity=70) } </style>

Enter any value from 0-100 (the lower you go the more transparent it becomes)
If you want to using it in iframes, add the above code to your pages
and add the following to your iframe document (bellow is an iframe example)

<iframe FRAMEBORDER="0" BORDER=0 name="inline" width=245 height=260 src="main.html" allowTransparency></iframe>

If you would like to see an example using this, go see my Natalie Portman site.
You can find it here. (Make sure you choose the Pop Up Version)