From Wikipedia:
“SlideShare is a Web 2.0 based slide hosting service. Users can upload files privately or publicly in the following file formats:PowerPoint, PDF, Keynote or OpenDocument presentations. Slide decks can then be viewed on the site itself, on hand held devices or embedded on other sites.[2] Launched on October 4, 2006, the website is considered to be similar to YouTube, but for slideshows.[3] The website was originally meant to be used for businesses to share slides among employees more easily, but it has since expanded to also become a host of a large number of slides that are uploaded merely to entertain.[4] Although the website is primarily a slide hosting service, it also supports documents, PDFs, videos and webinars.[5] SlideShare also provides users the ability to rate, comment on, and share the uploaded content. The current list of SlideShare’s investors includes Venrock, David Siminoff and Dev Khare.[6]“