If the main Toporama WMS site is unavailable, www.AlaskaMapped.org has the seamless canadian 250k topos scanned from NTS paper maps under the BDL Extras service (also see here). In the online map browser it's called the SDMI.Topo layer.
Toporama is is more up to date, has better resolution (1:50k) and let's you grab/leave-out certain layers while Alaska Mapped has better performance (and Arcgis layers if you want them).
I don't know if it still works, but a couple of years ago I hacked together a method for downloading the US Seamless National Elevation Dataset in bulk that might work for topo raster maps too.
To bypass the map viewer put the
coords on the URL like so:
http://extract.cr.usgs.gov/Website/distreq/RequestSummary.jsp?AL=71.0,56.0,-140.0,-150.0&PL=NAK01HZ
where this is your region of interest
north,south and east,west in decimal
degrees.
AL=71.0,56.0,-140.0,-150.0
and this is data set to choose from,
in this case “National Elevation
Dataset Alaska (NED) 2 Arc Second”
PL=NAK01HZ
If you use this technique, please be gentle. It’s not in our interests to force them to take protective measures and close this avenue.
Also don't overlook snail mail, it's high latency but has almost limitless bandwidth:
With regard to ordering the regional
CD’s:
“You can order the entire U.S. in 30
meter resolution in either ArcGrid or
GridFloat format. The data will be
provided on a 250 GB external drive at
a total price of $1005.00. This
includes shipping and handling. This
will cover the Conterminous U.S.,
Alaska (at 60 meter res), Hawaii, and
the territorial islands. We no longer
provide this on CD or DVD media.”
An incredibly good price in my
opinion.
The contact address is
webmapping@usgs.gov
Customer Service/Webmapping
Data and Applications Support
Department Science Applications
International Corporation (SAIC) at
U.S. Geological Survey - EROS (Earth
Resources Observation and Science)
47914 252nd Street Sioux Falls, SD
57198-0001
Phone: 1-800-252-4547
Fax: (605)-594-6589
Best Answer
Enjoy http://maps.vlasenko.net/soviet-military-topographic-map/
Update: There seem to be some torrent cache's of http://poehali.org/maps/ search at your own risk.
Below are some websites with varying degrees of content and geographic coverage.
University of Georgia Libraries: http://www.libs.uga.edu/maproom/collections/soviet.html
MadMappers.com Africa specific: http://www.madmappers.com/mapset.php?MS=182 http://www.madmappers.com/mapset.php?MS=183
One more source that claims to be 80 GB of data compatible with OziExplorer http://www.afanas.ru/mapbase/help Use a translator to read the help if needed. If you browse to the source of the downloads you can browse the directory and grab what you need after entering the credentials listed in the help file.
EDIT (2015-07-21): For anyone wanting more background information on these maps, and how they became "de-classified", WIRED did a great write-up.