Here's a pretty neat tool I recently came across. You can now view the Canadian topographic maps via Google Earth. This tool allows you to view the maps as a "layer", overlayed on the satellite photos. That means you can switch back and forth between the maps and the regular satellite view, or set the map layer to be semi-transparent so that you can view the satellite image through the topographic map. It will make measuring distances on topographic maps a snap.
Start playing with it for yourself by downloading it here: http://www.gelib.com/natural-resources-canada-toporama.htm
Thanks to Martin for letting us know about it!