AskDrWiki is an online repository for medial information modeled after Wikipedia. The project was started in early 2007 by four physicians looking for a quick way to share review articles, notes and images in cardiology. The site is a grassroots effort, and geared towards clinical audience- residents, interns etc.
Wiki’s are a good way to organize collective wisdom in any field, so the concept is valid. Problem with wiki’s are that 90% of content is written (and policed) by 10% of the users. When your potential audience is not a big number (only 100K or so residents enrolled in US every year) and nature of material necessitates careful oversight, all that translates into a very slow progress for content. Their homepage was last edited in Dec 07 and last blogpost was in April 08. The site draws a decent number of unique visitors though..in range of 5,000. Hope they gain momentum in future.