Web Metrics from a Google Study

A Google study based on "a sample of several billions of pages" reveals interesting statistics about the size, number of resources and other such metrics of pages on the world wide web.

Highlights:
The average web page takes up 320 KB on the wire.
Only two-thirds of the compressible material on a page is actually compressed.
In 80% of pages, 10 or more resources are loaded from a single host.
The most popular sites could eliminate more than 8 HTTP requests per page if they combined all scripts on the same host into one and all stylesheets on the same host into one.

It comes with some caveats. Thanks Annie Sullivan

There are simple tricks & free Web Performance Analysis & Optimization tools to overcome these speed barriers & make the web overall faster

Also see:

Web Security Tutorials from Google & MS
Google Browser Security Handbook