Question: I know of a couple tools to measure end user web site performance and I'm wondering what else is out there. The two major ones I know of are [yslow](http://developer.yahoo.com/yslow) and [Google's page speed](http://code.google.com/speed/page-speed).

Answer: 
What I've gotten in the habit of doing is loading up firebug, which measures every file loading to the ms, and then jumping on a proxy like Tor. Then I can see in real time which files are taking too long to load in say Germany or Australia. Usually at throttled speeds not much faster than dial up. 

I'm sure the other serveces mentioned are great but this is a real world way to do it.
[gtmetrix.com](http://gtmetrix.com) is similar to webpagetest.org, but another option as well.