MyWebspiration is a tool that is very similiar to Inspiration. As a teacher, you could go in and create graphic organizers and print them. You could also collaborate with your students on this site and create something together. Anything that you would have your students draw in class (like the water cycle), you could use this tool for. Then it will turn their picture into an outline, if you want.
MindMeister is very similar. It definitely looks like a great site to make graphic organizers, and there are many graphic organizers to browse and edit, if you choose. I like this better than Webspiration, for that reason. If you would use either of them to make graphic organizers, MindMeister would be much faster because you can edit the examples that are already there for you. It also looks like you could collaborate with your students.