tooltips

http://css-tricks.com/image-map-with-prototype-tooltips/

http://www.alistapart.com/d/cssmaps/stickymap/index.html

http://www.dynamicdrive.com/dynamicindex5/dhtmltooltip.htm

http://alt-web.com/Tutorials/tooltips-on-image-maps.html

http://www.dynamicdrive.com/dynamicindex4/imagetooltip.htm