It’s just been announced that Google’s Page Speed Online, the page speed testing tool that makes recommendations to speed up your website, has been given an API. Already there is a WordPress plugin using it, the W3 Total Cache WordPress plugin.
Check out the getting started guide, which should be enough for all you developers out there to get going.
I imagine this would be very useful for SEO agencies, they can plain label the page speed tool to make it look as though it is themselves that are providing it. Also for those companies that do automated analysis of their client sites, this would be a useful addition to their report, providing a few extra things to squeeze that little bit more out of a website.
Again it shows how seriously Google take user input, people ask for something and they do their best to provide it.
To read more, check out the announcement on the Google Webmaster Central Blog.