Google's new Page Speed Service takes many of the optimizations outlined in the company's Page Speed Online API and applies it to sites automatically.
It's a turnkey online service that automatically takes care of the optimizations by rewriting pages and delivering them to users using Google's servers.
The tool works by having users point the CNAME for their URL at Google's own servers. From there, Google can do the optimizations and rewrite pages as needed.
On the Google Code blog, Google says that it has seen speed improvements from 25% to 60% on some sites. Google has a gallery and a comparison test that users can try themselves.
Right now, the tool is only available to a limited set of webmasters, but you can request access by filling out this form. Google says that pricing will be competitive.