I know it's not a Google product, but maybe these samples can help
too. This allows you to overlay GIS data (including raster imagery)
from a GIS server on Google Maps. Sort of mashing the two worlds
together. There is a lot of data on GIS servers across the country,
so nice to be able to add other types of data.
Here's the link to that API.
http://help.arcgis.com/en/webapi/javascript/gmaps/index.html