Are there sources of free/open maps that would be useful for walking off-road in various areas of the world? In particular, are there maps that work with handheld mapping GPS units (e.g., Garmin ...
I know the USGS and many others offer free downloadable raster topo maps for almost anywhere. But what if I want vector maps using GPS coords? I'm new to GIS but I would assume there is a de facto ...
I have looked at offerings from MemoryMap and Anquet, but once you scale beyond a small area they become prohibitively expensive.