Wallwisher

Wallwisher is an online notice board maker.

For those who have never tried Wallwisher before, it is very easy to use. To get started simply go to Wallwisher.com and click "build a wall." Then title your wall, choose a URL for your wall, enter your name and email, and start adding sticky notes to the wall. Sticky notes added to a Wallwisher wall can contain up to 160 characters of text plus links to images and videos. You can choose to make your wall private or public. If you choose the public option anyone can quickly add sticky notes to your wall. If you want to approve additions to the wall before they appear, that's an option too. Choosing the public settings is allows for the quickest set-up and use of Wallwisher as you only need to give students the URL of your wall in order for them to add notes to the wall.

Check out these interesting ways to use Wallwisher in the classroom.
http://docs.google.com/present/view?id=dhn2vcv5_436f8kscmdc