We have found the following sites useful for various purposes:
http://cakephp.org/
http://www.ubuntu.com
http://creativecommons.org/
http://www.2600.com
http://www.2600.com/offthehook/
http://thenexthope.org/
http://www.thelasthope.org/talks.html
http://www.the-fifth-hope.org/hoop/
http://www.h2k2.net/panels.html
http://www.gnupg.org/
http://www.gpg4win.org/
http://www.eff.org
http://www.lostfilmfest.com/
http://www.textfiles.com/directory.html
http://www.linux.org/
http://www.opensource.org/
http://www.w3.org/
http://www.arrl.org