I made a browser map of our family Minecraft world. It is fun to look around at everything we have built without actually logging into Minecraft.
This uses Minecraft Overviewer to turn the saved world into isometric image tiles. The browser only needs the tiles for the part of the world you are looking at, so you can pan and zoom around instead of loading one enormous picture.
It is a snapshot from when the world is rendered, not a live feed from the server. Still a pretty fun way to explore our little world.