Intellipedia

US spies get a Wiki:

A "top secret" Intellipedia system, currently available to the 16 agencies that make up the US intelligence community, has grown to more than 28,000 pages and 3,600 registered users since its introduction on April 17. Less restrictive versions exist for "secret" and "sensitive but unclassified" material.

The system is also available to the Transportation Security Administration and national laboratories...

Intelligence officials are so enthusiastic about Intellipedia that they plan to provide access to Britain, Canada and Australia.