U.S. Citizenship & Immigration Services: http://www.uscis.gov/portal/site/uscis
Department of State Visa Services: http://travel.state.gov/visa/index.html
Complete list of embassies and consulates: http://usembassy.state.gov/
U.S. Department of State: http://travel.state.gov/travel/index.html
Foreign Consular Offices in the U.S.: http://www.state.gov/s/cpr/rls/fco/
Direct Airside Transit Visas: www.britainusa.com
Department of Homeland Security: http://www.dhs.gov/dhspublic/
Social Security Administration: http://www.ssa.gov/pubs/10181.html
SEVIS home page: http://www.ice.gov/sevis
Federal Registry (regulations) http://www.archives.gov/federal_register/code_of_federal_regulations/code_of_federal_regulations.html
