Web developer [mozilla.org](a must-have) has a speed analyzing tool by default (well, more of a link to a website that does the job), I prefer to use that one. Here's an example [websiteoptimization.com] of slashdot's report.

YSlow require Firebug to previously be installed in order to run. It is an extension of the capabilities of Firebug and so is an extension of an extension, a meta-extension if you will.

It provides download times for all kinds of connections, from 14.4K to 1.44Mbps. Also, seperate download times for objects.

We started with websiteoptimize here at Zillow, but Steve's tool is much more useful. His upcoming O'Reilly book is also quite good. We've taken seconds off our of our user response time with it. Steve came and spoke and it was very well attended and liked by a bunch of Seattle Web 2.0 folks.

If you put the links to the CSS at the very top of the head section then that grade will jump from an F to an A.

I doubt moving them above title makes any noticeable difference in the real world though.