I spend a LOT of time trying to optimize web applications to run and appear as fast as possible, one of the most valuable tools I have in my “bag of tricks” is the YSlow! plugin for Firefox.
It integrates in the browser and gives a near real-time scoring of the pages you visit and suggestions on how to improve them. While some of the suggestions are not practical (for example: use of a CDN) the bulk of them can be applied to your application code or server with a little bit of work.
The rules and scoring mechanisms are well documented at the following website:
The YSlow! plugin is available here:
Happy… Faster Surfing!