Google announces Google Knol. Knol stands for a unit of knowledge. Google tries to build a knowledge base with information provided by subject matter experts only.

Google will not serve as an editor in any way, and will not bless any content. All editorial responsibilities and control will rest with the authors. Google Knol will include strong community tools. People will be able to submit comments, questions, edits, additional content, etc.
The system is still under development and Google only started to contact experts to start contributing.
More details on the Google Blog.