scrolledIntoView.js

(function ($) {

    $.fn.scrolledIntoView = function(){
        var elem = $(this),
            docViewTop = $(window).scrollTop(),
            docViewBottom = docViewTop + $(window).height(),
            elemTop = $(elem).offset().top,
            elemBottom = elemTop + $(elem).height();
            return ((elemBottom >= docViewTop) && (elemTop <= docViewBottom) && (elemBottom <= docViewBottom) && (elemTop >= docViewTop));
    };

}( jQuery ));