Corkboard. me is a simple online post-it board. It does allow text and pictures, it's free, there is no registration and a unique URL is created for each board so the potential for collaboration is present. How simple is that?!
Scrumblr. It is amazingly simple to use. Go to the web site. Name your board and click Go.
New in blue appears. Each time you click the plus sign another word New appears along with a line. These lines are creating columns for your sticky notes. If you get too many columns they can be removed by clicking on the minus sign. To label the column headings double click on the word New.
To add notes, in a variety of colors, click on the plus sign in the lower left hand corner. Notes can be dragged to any location. By double clicking on the note text can be added and edited. Unwanted notes can be deleted. Next to the add note icon is a magnifying glass. Click on that to zoom in and out on the board.
In the lower right hand corner are a series of colored dots which can be used to prioritize or further label your notes.
Free to use without any registration is a major plus in using this type of application with younger students. Only people that have the unique URL can share the board. Adding to the board is anonymous which is inviting for those students that might be hesitant to speak their views.