SO jQuery Fiddle

Test Fiddle mainly for SO Questions jQuery 1.4.3, UI 1.8.5

by Nick Craver

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.5/themes/ui-lightness/jquery-ui.css">
<div id="c">Hover me!</div>
<div id="d">Dialog Content</div>

CSS

#c { width: 200px; height: 200px; border: solid 1px #ddd; }

JavaScript

$(document).ready(function () {
    $(document).mousemove(function (e) {
        $("#d").dialog("option", { position: [e.pageX+5, e.pageY+5] });
    });

    $("#d").dialog({
        autoOpen: false,
        show: "blind",
        hide: "explode"
    });
    $("#c").bind("mouseover", function () {
        $("#d").dialog('open'); // open
    });
    $("#c").bind("mouseleave", function () {
        $("#d").dialog('close'); // open
    });
});