A cursory search of both of these sites from time to time yields hundreds of presentations of various topics in health and medicine with 100s of pathology related material of varying quality which the user can judge for him/herself and rate/comment on.
Slideworld.org I have mentioned before and this site now contains 100s and soon 1000s of pathology images which can be viewed or downloaded. What impresses me most about these file sharing sites is the ease and speed by which you can upload, share and download large powerpoint or image files.
The other item is the number of users and colleagues who want to share information and comment or rate for future users. While some talks may be viewed and/or downloaded nearly 1000 times in a few months, the time to upload, name and attribute to myself literally takes a few seconds.
From: tissuepathology, 20 minutes ago
Medicine 2.0 Congress Medical Bloggers PanelToronto, CA Sept 2008