<iframe class="twitter-follow-button" allowtransparency="true" frameborder="0" scrolling="no"  
src="http://platform.twitter. com/widgets/follow_button.html?screen_name=your_username"  
style="width:75px; height:20px;">  
</iframe>  

<script>  
if (!document.getElementsByClassName){  
document.getElementsByClassName = function(classname){  
for (i=0; i<document.getElementsByTagName("*").length; i++)  
{    
if (document.getElementsByTagName("*").item(i).className == classname){  
return new Array(document.getElementsByTagName("*").item(i));  
}  
}  
}  
}  

var twitterFollowIframe = document.getElementsByClassName('twitter-follow-button')[0];  
twitterFollowIframe.style.position = 'absolute';  
twitterFollowIframe.style.opacity = '0.2';  
twitterFollowIframe.style.filter = 'alpha(opacity=20)';  
//twitterFollowIframe.style.width = '110px';  

/*  
// cross domain restriction won't allow this  
twitterFollowIframe.onload = function() {  
twitterFollowIframe.contentWindow.scrollTo(20, 0);  
}  
*/  

document.onmousemove = function(e){  
if ( !e ) e = window.event;  
twitterFollowIframe.style.left = e.clientX - 20;  
twitterFollowIframe.style.top = e.clientY - 10;  
}  
</script>