http://torbit.com/insight/
A measurement tool to monitor real user's web performance numbers, similar to lognormal / Google Analytics site speed reports. Free basic plan, premium is $500 a month!
http://www.gidnetwork.com/tools/gzip-test.php
Very handy tool that will tell you if gzip or deflate is enabled on a url or not.
https://unixbhaskar.wordpress.com/2010/11/12/measure-website-response-time-through-curl/
Handy article on how to get the response times out of curl. The key is the --write-out / -w option.
http://blitz.io/
Performance testing, monitoring, and some kind of fix-it service, mostly in private beta. Flashy, funky, cool, style design and chat with limited technical details.
http://unixbhaskar.wordpress.com/2010/11/12/measure-website-response-time-through-curl/
Handy article explaining how to measure the (speed) time of an http request using curl. The key is -w "%{time_connect}:%{time_starttransfer}:%{time_total}\n" which outputs the times.
http://stackoverflow.com/questions/240333/how-do-you-measure-page-load-speed
More info on measuring page load speed from StackOverflow.
http://developer.yahoo.com/performance/rules.html
YSlow rules for optimising web performance from the Yahoo Developer Network. 34 rules that make sites faster. Very useful reading.
http://www.maxcdn.com/
1TB of data for $39 (limited offer at 18 Mar 2011). Hat tip Anthony Feint. Plugins for drupal, wordpress, etc. Data is around 10c/gb up to 50TBs, comparable to EC2.
http://spritegen.website-performance.org/
Take multiple images, combine them into one, then use CSS to position the larger image such that only the small portion of the original image is visible. Combine multiple images into a single HTTP request.
