TIL that there is a fictional island in the South Atlantic off the west coast of Africa at lat/long 00 called 'Null Island'. Although it doesn't exist in reality it serves as an error trap for map systems. Map enthusiasts have given the island its own history geography and even flag.
GPSVisualizer--very cool mapping tool. And free. Just type in "Latitude, longitude" in the "Or Paste Your Data Here" box; hit return, then enter the lat and long you want to map, separated by a comma. Then click on "draw the map" Easy peasy.