Download MCMap Live and run it. From the file menu you can select Worlds 1-5 from single-player minecraft on your system or any world folder, including server worlds. Drag or two-finger scroll the map to move around. Scroll/Pinch to zoom in and out (or use the a and z keys if you have no scroll wheel). Use the menus to change lighting, etc. Play around, I'm sure you'll figure it out!
Download MCMap Live v1.4.1
For updates check the MCMap Thread@minecraftforum.net