http://www.mediauk.com
Probably the ultimate resource for radio news, jobs, and discussion.
http://www.browsershots.org
Free alternative to Browsercam, for testing websites in various different browsers.
http://www.w3csites.com
Collection of sites that conform to W3C standards. This site is an 'Editors Pick'!
http://www.sxc.hu
Thousands of free stock photos of almost everything imaginable.
http://www.famfamfam.com
Some really great icons, as used in my Radii CMS.