Web 2.0 Media Apps
Voki - Animated, Speaking Avatars
Xtranormal - Animated Digital Storytelling
Kerpoof - Various Apps - Animated "Movies," Digital Storybooks
Animoto - Photo/Video Editing App
Prezi - Non-Linear Presentation App
E2BN Learning Apps
Toy Theater - Several Art, Media, and Music Digital Toys
Glogster.com/edu - graphic/poster style blogs
Wordle - Word Cloud Art
Tagxedo - Shaped Word Cloud Art

Web 2.0 Digital Storytelling Apps
Picture Book Maker - Great for K-3!
Storybird.com - Writing with beautiful provided illustration
StoryJumper.com - Digital Book Maker where students create writing and illustrations
Myths and Legends Story Creator - Digital Storytelling App
Kerpoof - Various Apps - Animated "Movies," Digital Storybooks
The Mega Machine by Scholastic - Writing prompts with cool formats
Makebeliefscomix.com - Comic Maker
Wacky Web Tales - Part of speech “Mad Libs”

Web 2.0 Collaboration Apps -
Learn more here.
flockdraw.com - Art, writing, brainstorming, critical thinking/problem solving
dabbleboard.com - Art, writing, planning, research, brainstorming, critical thinking/problem solving
primarypad.com - Collaborative Word Processing
storybird.com - Writing with beautiful provided illustrations
Wikispaces.com - Collaborative Work Spaces/Websites

http://sophieproject.org/ - So new, I don't even have any samples, but the promised functionality of this program makes it something we should definitely be checking out!