Google launched their PageSpeed Service last year with the aim of improving the experience of web surfing, without making them a dime. The idea sounded great, as it worked like similar services such as Akamai, where it would boost web browsing speeds by caching pages in the same way, but as always, there's always improvements that can be made.
Google's latest PageSpeed beta uses some simple techniques that improve performance even more, using a new rewriter called "Cache and Prioritize Visible Content". Using this new tool, your browser will load content before it even appears "above the fold" before fetching text and photos that would be initially hidden on the page, all while prioritizing other content ahead of Javascript, which isn't needed as much as more basic elements.
Also, for pages that include HTML that isn't cacheable, such as personalized info, is returned, standard portions of the side and cache are displayed immediately, whilst other content loads in its normal fashion. This new tool isn't the best for every website on the web, but it's great to see these changes, all for free.