INEGI now have CD Roms with digital maps of Mexico. 1:250000 for most areas and 1:50000 of DF, Popo/Izta etc.

Great! Contact information? Cheers!

http://www.inegi.gob.mx

They have an online catalogue, but it's not very clear. You ought to be able to get thme via this.

They also have an online map...but its not (yet) any use.

They have outlets across the City. A convenient one is at the airport.

Of course, as the the topo maps come in .gif format, you could always breach copyright and get one via email from someone you know who's got one....

You can also get them from omni map:

http://www.omnimap.com/catalog/digital/dig-mex.htm

The also have digital maps for the following countries/continents:

http://www.omnimap.com/catalog/digital.htm