F1000 posters is a new website archiving research posters displayed at life sciences and medical conferences:
“The early scientific information presented in conference posters is universally agreed to be an important resource but, unfortunately, it is almost always completely lost once a conference is over. As a result, posters are only viewed by a handful of people before they disappear, either forever or until the research is later published as a paper. Some important work may never get published, particularly if it focuses on negative results or case studies. The system of removing posters from view after a conference is over represents a vast loss to the scientific community of unique and potentially valuable information.” (from http://posters.f1000.com/)
The site can be browsed by subject or conference, and conference posters can be deposited without any cost to the submitter (or to the viewer), increasing the visibility of your research.