Arizona: http://aria.arizona.edu/images
Arkansas: http://sal.uamont.edu/sal/default.htm
Delaware: http://www.rdms.udel.edu/rdms/gis/drgdlg
Florida: http://www.labins.org/drg.htm
Georgia: http://csat.gatech.edu/csat/drg/drg.html
Idaho: http://geolibrary.uidaho.edu
Illinois: http://www.isgs.uiuc.edu/nsdihome/ISGSindex.html
Kansas: http://gisdasc.kgs.ukans.edu
Missouri: ftp://msdis.missouri.edu/pub/drg
Montana: http://nris.state.mt.us/nsdi/drg.html
Nebraska: http://csd-esic.unl.edu/index.html
Nevada: http://www.nbmg.unr.edu/drg.html
New Mexico: http://sar.lanl.gov/topo_maps
http://rgis.unm.edu/data_entry.cfm (Hard to navigate but lots of data)
New York: http://www.nygis.state.ny.us
Pennsylvania: http://www.maproom.psu.edu/drg1
Utah: http://agrc.its.state.ut.us
West Virginia: http://www.dep.state.wv.us/metadata/index.html
Wyoming: http://wgiac.state.wy.us/wsdc/usgs/drg/aboutdrg.html
Upper Mid-western States (partial): http://www.umesc.usgs.gov/data_library/available_data.html
Washington and Oregon (margins cropped; won't geo-ref in Fugawi): www.reo.gov
Washington (uncropped USGS .DRGs): http://duff.geology.washington.edu/data/raster/drg/index.html