Technical Weblogs

I need to feed (pun intended) my hunger for technical weblogs and add a few more feeds to my blogroll.

I am particularly interested in weblogs that cover the following topics

• Software Development
• C
• Perl / mod_perl
• Ruby / Rails
• Apache
• Databases / MySQL
• Unix / Linux
• Clustering / Distributed Computing
• Network Security
• Cool Hacks / Geek Stuff

I've managed to track down a few good weblogs (see: my blogroll), but I'd like to know of others.

What's your favourite technical weblog? Who should I be reading?