Google Maps / Open Streetmap Latitude, Longitude Popup
Simply click on the map on a location and it will provide you with the latitude and longitude of the clicked location.
Based on code taken from these openlayers examples.
All other errors are caused by code written by Pierre Gorissen.
Update: 23-7-2013 The code has been updated to use OpenLayers and OpenstreetMaps by default. Google Maps is still available as option. Zoomlevel is now stored in permalink.