La combinaison de jQuery animate et CSS3 permet d'obtenir l'effet de poursuite au ralenti avec le code source download_jquery

<div id="container">
<div id="first"></div>
<div id="second"></div>
</div>

var $first=$('#first');
var $second=$('#second');
(function(){
move1();
move2();
})()
function move1(){
$first.animate({
"left":220,
"top": 0
},400).animate({
"left":220,
"top":220
},400).animate({
"left":0,
"top":220
},400).animate({
"left":0,
"top":0
},function(){
move1();
})
}
function move2(){
$second.animate({
"right":220,
"bottom": 0
},400).animate({
"right":220,
"bottom":220
},400).animate({
"right":0,
"bottom":220
},400).animate({
"right":0,
"bottom":0
},function(){
move2();
})
}