Slideshare

Popular site for uploading and sharing PowerPoint presentations.

Slideful

Create slideshows of images

Slide.ly

Create presentations with image and music. Easily share to Facebook. 

PresentMe

Add narration to your slideshow!

PowToon

Create animated videos and presentations for free. Login required.

Magisto

A video mash-up site or app for presentations.

eMaze

A presentation site that is a cross between Prezi and PowerPoint and can be embedded into another site. Login required.

AuthorStream

A great way to upload and share PowerPoint presentations online, similar to SlideShare.

Slide Rocket

Jux

Create a slideshow using pictures and the backgrounds.

Knovio

Add video and audio easily to your slideshow presentations.

Shwup

Create collaborative slide shows using movies and videos that can be shared privately between users.

Prezi

Sign-up to create free online presentations.

Kizoa

Create free online, animated slideshows that can be burned to a DVD. Sign-in required.

Magic Studio

Create interactive presentations by adding video and audio.  Sign-in required.

PreZentit

www.docs.google.com
www.beta.joggle.com
www.slide.com
www.spresent.com
www.zoho.com