I'm created a very large map with many poly areas (over 20 coordinates each) for regions within the map. However, you can't add css to the AREA tag as I was told it's not a visible element. What I want to do is when the user hovers over an area on the map, I want it to be "highlighted" by applying a 1px border to the specific AREA element. Is there a way of doing this? No, I'm not going to resort using rectangles.
Not possible with CSS.
You might check out the Map Hilight jQuery plugin, though.
EDIT 10.2011
ImageMapster is a more recent, and more powerful plugin you should also check out.