Slideshare.net is a site the I recently found that allows anyone with PowerPoint or OpenOffice Impress to post a slide show on the web and share it with the world. It is kind of like YouTube for Slideshows. It is free and easy to use. Instructors can use this to post their presentations on a public website. Conference Speakers can post their slides after their presentation to their audience. And this is a better way to distribute your presentations without giving away your PPT files.
Students can also use this sharing their presentations with the class or the world.
Other features allow you to receive comments on your slideshows and embed them into other websites or blogs. It is kind of like having a free Breeze Presenter server available only without the audio. But will that be the next new feature?