Measure and optimize your website speed with Google Page Speed
Saturday, June 6th, 2009Google introduces Page Speed, a new and a great utility to measure and optimize your website load time.
It's an addon integrated with the well known Firebug for FireFox, and it's a tool that Google used internally to improve the speed of their web pages, now it's public, open-source, and everyone can download it from here
In my opinion, the best thing is the
Google Page Speed - Overall performance summary
Page Speed Activity