Maps, get your maps
Doing some work at home, I stumbled across .gov sites with block- and tract- level maps of almost every county in the country. They're FTP sites, but the PDF maps are current from 2001. Wonder how long before this gets pulled down to save us from "the terrorists"?
Block maps (FTP)
Tract maps (FTP)
County voting districts (each 000.pdf is an index)