Hill Shading on Google Maps

Gmap4 is a Google Maps based interface for viewing detailed topographical maps of the USA and Canada.

The application allows the user to view a number of topographical base maps using the familiar navigation tool of Google Maps. The app also comes with a really neat hill shading effect that allows the user to adjust the hill shading on the 'Topo High' map view.

Gmap4 contains a whole host of other useful features, such as route planning and the ability to view KML, KMZ, GPX and TPO files. It even has a feature that lets you view your GPS tracks in 3d using the Google Earth browser plugin.