Rules for high performance websites.

Read on, ive kind of memorized it already

http://stevesouders.com/examples/rules.php

Joomla site from 800kb to 133kb, Gziping, Minimizing CSS&javascript plus html optimizing.
Makes your site more attracive due to superspeed! Zoooom!!!

(I Know not ModX exacly related, but you shure can use it for many places in ModX to!)

well tips are nice and i think we should keep these in mind for a fast loading website

I wonder how the "Expires" header is handled by ModX. Is it by default used ? (sounds good if it is so :p).