CssMapMarker is a project mainly written in JavaScript, it's free.
CSS Driven Markers With Google Maps
The CssMapMarker object supports the following options.
Required: map - the map to which the css marker should be added marker - the marker to which the css marker should be bound
Optional: id - The element id to be used on the marker innerHTML - HTML to append to the marker className - the class name to use on the marker. (default: cssmapmarker) onDrawn - callback function for when the css marker is drawn onAdded - callback function for when the css marker is added to the map