How do I detect whether a browser supports mouseover events?

Question

Let's assume I have a web page which has some onmouseover javascript behaviour to drop down a menu (or something similar)

Obviously, this isn't going to work on a touch device like the iPad or smartphones.

How can I detect whether the browser supports hover events like onmouseover or onmouseout and the :hover pseudotag in CSS?

Note: I know that if I'm concerned about this I should write it a different way, but I'm curious as to whether detection can be done.

Edit: When I say, "supports hover events", I really mean, "does the browser have a meaningful representation of hover events". If the hardware supports it but the software doesn't (or vice versa), there's no meaningful representation. With the exception of some upcoming tech, I don't think any touch devices have a meaningful representation of a hover event.

Answer 1

This method catches more devices/browsers

try {
   document.createEvent("TouchEvent");
   alert(true);
}
catch (e) {
   alert(false);
}

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Answer 2

var supportsTouch = (typeof Touch == "object");

Just detect if it's a touch device and then do your special stuff. This is the simplest approach since most touch devices emulate mouse events but no mouse driven device emulates touch events.

Update: Considering how many devices there are now a days and Johan's comments I'd recommend simply using Modernizr.