Endless vertical scroll

CSS

body {
    height: 1600px;
    background-image: url("http://img807.imageshack.us/img807/6054/tall01.jpg");
    background-position: top center;
}

JavaScript

var bgHeight = 1600; // pixel height of background image

$(document).ready(function() {   
    $('body').height( bgHeight + $(window).height() );
    $(window).scroll(function() {
        if ( $(window).scrollTop() >= ($('body').height() - $(window).height()) ) {
            $(window).scrollTop(1);
        }
        else if ( $(window).scrollTop() == 0 ) {
            $(window).scrollTop($('body').height() - $(window).height() -1);
        }    
    });
});
$(window).resize(function() {
    $('body').height( bgHeight + $(window).height() );
});