javascript fun

so i recently discovered thefun of putting js right into the address bar.  things like

javascript:while(1){window.open()};
or
javascript:while(1){alert()};

but what i'd like to know is what can you come up with?  my skills are far from special, i bet 4chan can come up with some good ones

paste the following into the address bar once a page has loaded.
EPIC JAVASCRIPT MANEUVER

javascript:x=0; e=document.body; e.style.position="absolute"; function rt(){e.style.top=100-(50*Math.cos(x*Math.PI/180))+"px"; e.style.left=100+(50*Math.sin(x*Math.PI/180))+"px";x+=5}; setInterval("rt()",50); void(0);