Harold Asmis at Ontario-geofish had discovered how to download free topo maps for the Garmin:
As I prepare for my tiny canoe trip, I found a way to get 1:50000 topo sheets on my Garmin 60cx! This is great! You can find the img maps on Mapcenter2, and you just download them on the Garmin, making that stupid file name change. And voila! Ready to canoe.
I discovered that you can switch to terrain maps in Google as well as plain maps or satellite images.