Presentations and Slideshows

Knovio - create and share online presentations with video and audio commentary

PhotoPeach - create online slideshows. Allows background music

Present.me - add a split-screen webcam recording to an existing PowerPoint, prezi, google doc or pdf

Prezi - online presentations with a zoomable canvas

VoiceThread - add voice comments from multiple users to a single presentation.

Zentation - allows you to sync a presentation to a YouTube video in a very unique way

Powtoon - make great looking animated videos and presentations