Here's a few tools I picked up at the Affiliate Summit New York Meetup. Thanks to Vinny O'Hare. I'm still trying to understand how to read results, so feel free to leave a helpful comment.
As an aside, the benchmark Google standard is believed to be 4 seconds for page loading. As a suggestion stack rank pages and bring time load times of worst performers. By fixing the outliers, you'll bring the average load time for the entire site. Of course look at your server, size or compression of picture.
Online Page Speed Tools
Smush.it from Yahoo
PageSpeed – an open source browser add-on
Some tools suggested by Reel SEO