An interesting link:
http://feedproxy.google.com/NationalTerrorAlertResourceCenter
The page gives a costant feed of terror and security-related situations from all around the world. Lots of things that aren't covered by local or national networks.
Another one of interest:
http://visz.rsoe.hu/alertmap/index.php?smp=&lang=eng
Worldwide "situation" map of disasters, emergencies, chemical spills, epidemics, etc...