At the Velocity 2010 conference, Google said that header compression can yield big gains:
Hölzle noted a glaring inefficiency in the handling of web page headers, which provide information about a user’s IP address, browser and other session data. The average web page makes 44 calls to different resources, with many of those requests including repetitive header data. Holzle said compressing the headers produces an 88 percent page load improvement for some leading sites.
How does one ensure that the response headers sent by the web server are compressed? Is this even possible with today's technology?