http://www.activa.com.au/js/jquery.hoverintent.js

1(function($) {
2    $.fn.hoverIntent = function(f, g) {
3        var cfg = {
4            sensitivity: 7,
5            interval: 100,
6            timeout: 0
7        };
8        cfg = $.extend(cfg, g ? {
9            over: f,
10            out: g
11        } : f);
12        var cX, cY, pX, pY;
13        var track = function(ev) {
14            cX = ev.pageX;
15            cY = ev.pageY;
16        };
17        var compare = function(ev, ob) {
18            ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
19            if ((Math.abs(pX - cX) + Math.abs(pY - cY)) < cfg.sensitivity) {
20                $(ob).unbind("mousemove", track);
21                ob.hoverIntent_s = 1;
22                return cfg.over.apply(ob, [ev]);
23            } else {
24                pX = cX;
25                pY = cY;
26                ob.hoverIntent_t = setTimeout(function() {
27                    compare(ev, ob);
28                }, cfg.interval);
29            }
30        };
31        var delay = function(ev, ob) {
32            ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
33            ob.hoverIntent_s = 0;
34            return cfg.out.apply(ob, [ev]);
35        };
36        var handleHover = function(e) {
37            var ev = jQuery.extend({}, e);
38            var ob = this;
39            if (ob.hoverIntent_t) {
40                ob.hoverIntent_t = clearTimeout(ob.hoverIntent_t);
41            }
42            if (e.type == "mouseenter") {
43                pX = ev.pageX;
44                pY = ev.pageY;
45                $(ob).bind("mousemove", track);
46                if (ob.hoverIntent_s != 1) {
47                    ob.hoverIntent_t = setTimeout(function() {
48                        compare(ev, ob);
49                    }, cfg.interval);
50                }
51            } else {
52                $(ob).unbind("mousemove", track);
53                if (ob.hoverIntent_s == 1) {
54                    ob.hoverIntent_t = setTimeout(function() {
55                        delay(ev, ob);
56                    }, cfg.timeout);
57                }
58            }
59        };
60        return this.bind('mouseenter', handleHover).bind('mouseleave', handleHover);
61    };
62})(jQuery);