Image menus are a hot design item, especially for getting attention to your primary products. You have one image to get attention, then when the user puts the mouse on the primary image, the image changes. The rollover image can be a different view of the default image, or it can be a completely different one. The image usually has a link so that it work as a "call to action" to get the user to visit the link.

Rollover menus like this are often done as Flash objects. That is a slick way to do things, but also an expensive way as these custom Flash menus can be quite costly. Once they are done, they are also impossible for non-technical people to edit. The Flash is fixed and final, so changes to your product line, event schedule, Website content, etc. will not be reflected in the Flash. At CorFun, we've dealt with this problem by creating an inexpensive Joomla module that gives you the rollover image menu effect, but without all the headaches.