Click on the interactive map to view statistics on all the counties in the continental U.S. Great nonfiction element to pair with a literature with a migration theme.
Great site for making mind maps and doing online brainstorming. Able to be exported and shared with others. Great tool for teacher collaborators and for kids! Super easy to use
graphical knowldege engine; might be useful in classroom to compare books, etc. More recently I tried inserting term (community) and was impressed with the automatically generated web/semantic map.
CmapTools (free, of course) allow for the developing of concept maps and you can link to images, videos, documents, etc. Not quite as flexible as Inspiration (which is my favorite, but it costs money), but a good option.
Blog about tools for drawing diagrams--free ones as well as paid ones. I particularly like (Inspiration--$ because you can hyperlink and save as a Word document with hyperlinks too--as well as bubbl.us--free.