Image mapping is an interesting method of breaking down an image to display added information like clicking to a link or offering more specific details on an image.
The common way it seeems to be used is by breaking the image and by hovering specific areas shows a specific detail for that area. Recently I have come acrossed this method to try to recreate this nifty annotation widget I saw on a blogging site. What the annotation does is it allows the user to click an area of the image and take a snapshot of it where the user can make a comment of that particular detail on the image. Another way this is used where everyone is familiar with is the facebook photo tagging.
In my circumstance I mapped an image of a car, detailing each car part. So when the user creates a snapshot it will also include the name of the part.
I'm still experimenting the whole thing.. more to come later.