I learned about a great tool called pingdom.com from a fantastic interview and webinar with Yoast. If you run a WordPress blog and want to get the most out of it you owe it to yourself to watch it and implement some of Yoast’s suggestions. and consider some fo the that shows a waterfall timeline of your site loading.
One of the big things I found was how much time some of the social media plugins take to load and sync with some of the social media sites. In some cases these were adding a full second to my site load time. Yoast jokingly suggests a good site loading time is zero, but concedes that under two seconds is where you want to be. Not only does site loading time matters to your visitors, it can also affect how you rank on Google.
Another place I noticed a lot of page loading time was a plugin that provided nicer formatting (syntax highlighting) for code blocks, configuration steps, and error messages. To remove the need for this plugin I converted all the code blocks to html. Two useful online tools for doing this are: