Maryland
Montgomery County, https://www.montgomerycountymd.gov/apps/tax/index.asp

Virginia
Alexandria City, http://realestate.alexandriava.gov/index.php?action=address
Arlington County, http://www.arlingtonva.us/DEPARTMENTS/Real...DREADefault.asp
Fairfax County, http://icare.fairfaxcounty.gov/Search/Gene...px?mode=ADDRESS
Loudoun County, http://inter1.loudoun.gov/webpdbs/default.htm
Prince William County, http://www4.pwcgov.org/realestate/LandRover.asp

Source: http://121space.com/index.php?showtopic=22400