“Google Code Blog: Introducing Page Speed”

Page Speed is a tool we’ve been using internally to improve the performance of our web pages – it’s a Firefox Add-on integrated with Firebug. When you run Page Speed, you get immediate suggestions on how you can change your web pages to improve their speed. For example, Page Speed automatically optimizes images for you, giving you a compressed image that you can use immediately on your web site.

Very interesting tool. Page Speed doesn’t like my :hover rules deep in the CSS hierarchy, for instance — it seems to me that browsers should be able to optimize that kind of thing, but I guess some may not, and Google certainly knows better than me.