Microsoft Powerpoint is an immensely powerful suite, and can be used for much more than straightforward presentations. It can be used to create website mockups, and even interactive learning tools.
"Create: bring "flat" PowerPoint® slides to life with your webcam, microphone
Edit: make changes, without the need for video editing software or skills
Share: publish instantly to private spaces or your social networks"
Most of these we've heard of or used - like Zoho and Google presentations... but others, I'm looking forward to checking out. If anyone has used some of these, I'd be interested in your feedback! :)
Brainshark is a competitor to Slideshare.net, allowing anyone to upload a PowerPoint or PDF to their Web service and annotate the visuals with audio/video comments or music.
"Zentation combines video and slides to create online presentations that best simulate the live experience. Easily create high-end webinars, webcasts, elearning, training and virtual events."