I wrote an article about this a few months ago, and wrote a little code test to see whether the iPhone touch based system correctly handled touch events by triggering both onhover and ontouch for touch events:
So theoretically on touch devices such as the iPhone/iPad a touch is the same thing as a hover in cases where there is no onclick handler, but in elements that have both an onhover and an onclick handler the onhover handler will execute extremely quickly, then the onclick handler will be called, so hover effects could be missed completely.
The best bet is clearly to avoid using onhover for important things.
The solution to this problem is really simple. Don't use onHover for anything important... But, the same could be said for flash or even plain old JavaScript etc.
I think the real solution is focus on the most basic browsers. Most websites work just fine as a simple web 1.0 website and while you can add optional features from there which fail gracefully. Rather than the normal approach of starting with the feature rich site and try to be useful as you strip away pieces.
http://experimentgarden.blogspot.com/2010/02/touch-based-web...
So theoretically on touch devices such as the iPhone/iPad a touch is the same thing as a hover in cases where there is no onclick handler, but in elements that have both an onhover and an onclick handler the onhover handler will execute extremely quickly, then the onclick handler will be called, so hover effects could be missed completely.
The best bet is clearly to avoid using onhover for important things.