UPDATE 2: The Web Accelerator is no longer available.
UPDATE 1: Installing the Google Web accelerator can cause various unexpected issues while surfing. See Google Web Accelerator Security Hole? post for more info before installing.
Google's new Web Accelerator software plugs into your web browser and speeds up page retrieval for snappier surfing.
How it works: Web Accelerator only downloads changes to pages you have viewed before; it pre-fetches pages before you click on the links; it compresses web data for faster transfer and "manages your internet connection" to optimize it for surfing.
The good news: it does save you time, in fact, the exact amount of time is calculated and viewable right inside your browser toolbar. And even if it is fractions of a second, it's satisfying to watch that number go up throughout the day.
The bad news: The privacy policy is "not the usual Yada Yada" (Google's words.) To install, you have to check a box which says, "I understand that personally identifiable information about me may be sent to Google while using the Google Web Accelerator" [view image], so that's a dealbreaker for surfers who value their privacy. The Web Accelerator is only worth it for broadband (cable/DSL) users and works for Firefox and Internet Explorer out of the box. Free, Windows only.
Web Accelerator [Google via Google Blog]