There is a pure CSS solution I'm currently using.
Add a body ID (or class) identifying your pages and your menu items, then use something like:
HTML:
<html>
<body id="body_questions">
<ul class="menu">
<li id="questions">Question</li>
<li id="tags">Tags</li>
<li id="users">Users</li>
</ul>
...
</body>
</html>
CSS:
.menu li:hover,
#body_questions #questions,
#body_tags #tags,
#body_users #users {
background-color: #f90;
}