Simple Surface is an online whiteboard tool that I initially reviewed a couple of years ago when it was known as My Simple Surface. The "my" was dropped from the name because the tool is now a collaborative tool. With Simple Surface you can collaboratively create outlines and mind maps.
To get started with Simple Surface just click on "use for free now," double click on the surface, and then start typing. To create an additional thought box just double click anywhere on your board. To make sibling and child thought boxes use the enter and tab keys. You can edit the color and size of fonts. Your boxes can be linked to URLs too. Right-click on your surface to open the full menu of editing options.
Applications for Education
Simple Surface could be a great tool for students to use to create webs and mind maps to plan creative stories, draft outlines for research reports, or diagram a set of concepts they're trying to connect. You could also have students use Simple Surface as a storyboard tool to plan video projects.