A CanvasLayer library has been added to the Google Maps Utility Libraries. The library allows Google Maps API developers to easily add a canvas layer as an overlay on Google Maps.
Using canvas with Google Maps can have many advantages. Brendan Kenny and Paul Saxman recently discussed the CanvasLayer library in a Google Maps Developers Office Hours broadcast. You can watch the broadcast here to view just some of the possibilities of using the CanvasLayer library with Google Maps.