Minecraft Overviewer is a utility designed to make it easy to create Google Maps-style maps of Minecraft worlds.
One of the nice things about the Minecraft Overviewer project is that the documentation is outstanding. It took me about 10 minutes to follow the instructions to install it on my Minecraft server and then generate a map of the world my son and I have been playing Minecraft in.
The Overviewer also does have a lot of options that are set in a configuration file, so you can set alternative texture packs for rendering or improve/decrease the smoothness of the rendering, etc.
There is a Windows version as well and good documentation for how to generate a map of single player worlds.
