iJET Travel Intelligence
Commercial organisation providing detailed travel advice and warnings for various destinations.
http://www.ijet.com

Fielding's DangerFinder
A somewhat 'gung ho' approach to dangerous places but contains detailed information about how to keep safe in some of the world's most dangerous places. Also has a traveller's bulletin board.
http://www.comebackalive.com/df/dplaces.htm

expatexchange.com
Registration for email newsletters containing critical travel warnings designed for US expatriates.
http://www.expatexchange.net/expat/index.cfm?pr=newslettercen

Air Security International's Hot Spots
Detailed listing of security related news items from around the world updated daily.
http://www.airsecurity.com/hotspots/HotSpots.asp#Amer

Travel Safety Information
Official travel advice and warnings from the New Zealand government.
http://www.mft.govt.nz/travel/

Sign in Safe
Offers the latest travel safety news, along with tools to monitor the safety of people as they travel.
http://www.signinsafe.com/

Foreign Affairs Canada: Travel Reports
Canadian government's official travel advice.
http://www.voyage.gc.ca/dest/ctry/reportpage-en.asp

Red 24
Security service with threat level analysis for business and personal travel itineraries.
http://srva.red24.info/nonmembers/

UK Foreign & Commonwealth Office: Travel Advice by Country
British government official travel advice and warnings for all countries.
http://www.fco.gov.uk/servlet/Front?pagename=OpenMarket/Xcelerate/ShowPage&c=Page&cid=1007029390590

Australian Department of Foreign Affairs and Trade
Official travel advice for Australians covering all destinations.
http://www.smartraveller.gov.au//index.html

U.S. Department of State: Travel Warnings & Consular Information Sheets
US government's official travel advice and travel warnings. Registration for automated email updates.
http://travel.state.gov/travel/cis_pa_tw/cis_pa_tw_1168.html