This is kind of a cool concept, reminds me of hackthissite.org from back in the day:
http://jarlsberg.appspot.com
I haven’t really done anything with it other than play around for a minute or two on it, this is the best I’ve done so far (upload as a snippet):
<img src="http://media.ebaumsworld.com/picture/PhantomPooper/PWNT.png" onmouseover="window.location='http://1227.com'" style="position: fixed; top:0; left:0; width:100%; height:100%;" />
