How do I rotate an element to 180 deg over 150 ms on hover?

On mouse over, I need to rotate an element counterclockwise 180˚ over an interval of 150ms, and then on mouse out I need to rotate the element counterclockwise back to the original 0˚ over 150ms.

I am open to using CSS3, jQuery, and JavaScript.

I use Chrome, but I also need to make it work for Firefox and Safari. Not too worried about IE.