Like a dream come true:  Prof. Zachary Schrag and his grad students in History at George Mason University have set up a wiki for 20th Century U.S. History called the Mason Historiographiki:

The Mason Historiographiki is a wiki (collaborative website) designed to be used by graduate students in history at George Mason University who are preparing for written or oral comprehensive examinations as well as by anyone interested in their take on the literature of history. In its initial incarnation, it will focus on twentieth-century United States history.

I really love this idea and would like to see it expanded.  While it would be prefereable to have a history wiki sponsored by AHA (or some other central organization) that updates The American Historical Association’s Guide to Historical Literature, it would be worthwhile for individual history departments to set up something similar for their grad students.

P.S. - Dr. Schrag's website links to a number of great resources for grad students (e.g., "The Anatomy of a Ten-Page Paper" or "How to Write a Review")

[links from edwired]