This is a late announcement here, but phpMap 0.1 was released a couple weeks ago. Why am I announcing it here? Becuase it's my project! What does it do? It's an online, php-based map program. Right now it's still in very basic form (it only allows image zooming and navigation), but in the future it will also include location recognition, database tie-ins to retreive additional information, location pinpointing, a menu-based navigation system, etc.
For more information, see the phpMap web page. To see it in action, check out the Ole Miss Campus Map. Remember, though, that most of the features in the Campus Map are not currently present in phpMap.