Here's a powerful online presentation sharing engine that not only allows you to upload your PowerPoint presentations online for free, but also assists you to share
them with your friends, students or co-workers located across the globe.

authorSTREAM is a great online community that gives you access to numerous
presentations on varied subjects uploaded by community members. You can find
exciting presentations on just about any topic, rate them, post a comment and
even embed them in your blog.