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!
Very handy tool that will tell you if gzip or deflate is enabled on a url or not.
Handy article on how to get the response times out of curl. The key is the --write-out / -w option.
YSlow rules for optimising web performance from the Yahoo Developer Network. 34 rules that make sites faster. Very useful reading.