Back to the article Using Multiple HTML5 Canvases as Layers
Here's the source code.
This example is coded for readability and not for optimized operation. All you need is a text editor like notepad, a copy of the image city.png (rightclick and save it) and an HTML5 friendly browser (I'm using Firefox 3.6).
You can copy this code and paste it into a new file called something like layers.html with the city.png image http://html5.litten.com/layers/city.png (they must be in the same directory) and when you open it with an HTML5 friendly browser like Firefox 3.6 it will display the stacked canvases.
Canvas Layers Test