SlideShare is the best way to share your presentations with the world. Let your ideas reach a broad audience. Share publicly or privately. Add audio to create a webinar.

Some of the things you can do on SlideShare

- Embed slideshows into your own blog or website.
- Share slideshows publicly or privately. There are several ways to share privately.
- Synch audio to your slides.
- Market your your event on slideshare.
- Join groups to connect with SlideShare members who share your interests
- Download the original PowerPoint / Pdf file

Link: http://www.slideshare.net/