USGS DOQQ imagery for Virginia is no longer hosted on this site. The following two sites allow for downloads of the DOQQs along with many other datasets.
The GIS Spatial Data Server is provided by the GIS Center at Radford University. DRGs, DOQQs, and DEMs are available for download.
UVA Virginia Gazetteer
The Virginia Gazetteer is part of UVA's Geospatial and Statistical Data Center. DOQQs, topographic maps, and terrain models are available for download.