Handy article introducing chef and providing a few links. A little out of date now, but provides a useful intro.
Interesting article on how webpop built their infrastructure on Rackspace's cloud. Includes links to a few useful tools (chef, wormly, new relic, nagios, ganglia, and others).
Very detailed article explaining how Magento implements its caching mechanism. It seems to be some custom classes layered on top of Zend's caching framework. Useful read.
Excellent article describing in depth how to have PHP store session data in memcached and the differences between the memcache and memcached implementations in PHP. Very useful.
On premises cloud computing platform, with an open source angle. Don't fully understand it.
A platform to manage cloud computing resources, deployments, and so on. Essentially a simplified front end for AWS as far as I can make out.
Another cloud based scale solution for MySQL, aims to simplify deploying MySQL "in the cloud".
Cloud based database that tries to achieve a new type of scalable, highly available, fault tolerant persistent data storage layer in "the cloud".
Interesting write up by James at Incsub on how they handle scale on edublogs. Some good advice although a little light on specifics, a good starting point for research.
Robert Scoble hosts a webinar session on avoiding the fail whale at scale. Includes the guy who built Gmail and now Friendfeed, Technorati and iLike.