Just came across Wallwisher (www.wallwisher.com)...the tool essentially creates a desk where anyone can post "sticky notes". The sticky notes are limited to 160 words, can include links for images, audio or video and can then be moved around the desk. Wallwisher can be used without an account, but it does need an email address (it will email you with a temp. password to access your wall).
Each wall you create can be named, emailed and embedded. Walls can be public or private and people don't need an account to post on a public wall. Only the creator of a sticky note can permanentaly move the note & the creator of the wall can edit the entire page at any time.
Classroom Applications: One concern before using this application...there is very little control if it is going to be used with students: they don't have to login to post. (blessing and curse)
1. Debates: I am going to try it out as a forum for a debate about Abraham Lincoln.
2. Student organizational tool before writing a paper. (sticky notes can be moved to structure an essay before it is written)
3. Collaboration: students can contribute to small group projects without having to physically meet up after school.