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: 
AOL's [WebPageTest](http://www.webpagetest.org/)
[gtmetrix.com](http://gtmetrix.com) is similar to webpagetest.org, but another option as well.