JavaScript prank (images dance on webpage)

prank.js

R=0; x1=.1; y1=.05; x2=.25; y2=.24; x3=1.6; y3=.24; x4=300; y4=200; x5=300; y5=200; 
DI=document.getElementsByTagName("img"); DIL=DI.length; 

function A() {
    var i;
    var DIS;
    for(i=0; i-DIL; i++){ 
        DIS=DI[ i ].style; 
        DIS.position='absolute'; 
        DIS.left=(Math.sin(R*x1+i*x2+x3)*x4+x5)+"px"; 
        DIS.top=(Math.cos(R*y1+i*y2+y3)*y4+y5)+"px"
    }
    R++
}
setInterval('A()',5); 
void(0);

Ideal for using as an april fools joke on your site (just make sure, the animations do not run forever, otherwise it becomes more of an annoyance than a joke :) ).