Hi folks,
Not sure if this link has been posted before (if so, please forgive). The University of Texas at Austin has a nice "one-stop-shop" selection of of online and browsable topographic maps for many areas in Mexico, Central and South America. These may be useful for travel/logistics and planning purposes.
Here's a link to the current index/coverage:
http://www.lib.utexas.edu/maps/jog/latin_america/index_map.jpg
Here's the link to the maps:
http://www.lib.utexas.edu/maps/jog/latin_america/
Disfruta!