What are some alternatives?
SlideShare - Discover, Share, and Present presentations and infographics with the world’s largest professional content sharing community.
Prezi - Welcome to Prezi, the presentation software that uses motion, zoom, and spatial relationships to bring your ideas to life and make you a great presenter.
authorSTREAM - authorSTREAM enables presenters to upload & share PowerPoint, Keynote & PDF presentations online; embed in blogs, convert to video and share on social networks.
Powerpoint - Explore how PowerPoint can help you tell a powerful story in your presentations and easily share your slides on the web.
Scribd - Unlimited books, audiobooks & comics. Unparalleled discovery. Any device. $8.99/month
emaze - emaze - Online Presentation Software – Create Amazing Presentations