Security Resources

• Astalavista
• SecurityDocs
• SecurityFocus
• GData: Online MD5 Hash Database (over 100 million entries) (removed)
• md5.crysm.net (over 27 million entries)

Hacking challenges

• HackThisSite.org
• HackQuest
• Try 2 Hack
• HackIts.de
• HackersLab.org

Free Shells

• FreeShell.org (telnet: sdf.lonestar.org)
• Cyberspace.org (telnet: nyx.nyx.net)
• Nyx.net (telnet: nyx.nyx.net)

News For Nerds

• Slashdot.org
• The Register

Educational

• HowStuffWorks
• Hack This Site

Webcomics

• VGCats
• Little Gamers
• Concerned: The Half-Life and Death of Gordon Frohman
• Penny Arcade
• PvPOnline
• Ctrl+Alt+Del

The Webcomic list: A huge list of webcomics

Other links

• KaffePrat.com