Google opened its new Knol service to the public today. The company announced Knol last December.

Knols are authoritative articles about specific topics, written by people who know about those subjects. The key principle behind Knol is authorship. Every knol will have an author (or group of authors) who put their name behind their content. It's their knol, their voice, their opinion.
With Knol, Google introduces a new method for authors to work together that they call "moderated collaboration.
Google also announced an agreement with the New Yorker magazine which allows any author to add one cartoon per knol from the New Yorker's extensive cartoon repository.

Adding cartoons to papers and presentations is a thing that got me through University. They nicely distract from the content.
Knol is accessible on knol.google.com.