Cybersecurity

Security sites on the web:

The BUGTRAQ list of newly revealed exploits, vulnerabilities, and warnings.
U.S. DOE-CIAC (Computer Incident Advisory Capability) Website with Dept. of Energy notices.
Internet Security Systems "X-Force" maintains an "AlertCon level" indicator and warnings. This site maintains that an unprotected device on the Internet will be compromised minutes to hours after being connected - and that's level 1, the "green" condition!
SANS intrusion detection page has an excellent review of intrusions, responses, and network security information, with a wide variety of additional security information in their reading room.