Bruce Schneider's blog: The guy who invented the Blowfish encryption algorithm.
system76: A great shop where to buy Linux-based machines (with or without OS).
Passmark software: CPU benchmarks.
The Poster: Free poster about the history of informatics.
Oracle-base: How to install Oracle 11 on Fedora 9 (FC9).
DynDNS: DynDNS service.
Apache & SSL: How to install SSL certificates on Apache.
Apache & Webdav: How to install Webdav for Apache.
Webdav & Windows: How to connect to Webdav servers in Windows.
stonki.de: How to set up Postfix on Gentoo.
MultimediaWiki: Very useful MPlayer FAQ.