I am trying to expose my colleagues to great open source (or otherwise free) software. So far they use or have access to Moodle, Audacity, Sketchup, Google Earth, Tuxpaint, and of course Firefox. For web site maintenance we use Joomla! We have MS Office, so Open Office and friends are not really necessary. I have contemplated exposing them to The Gimp, or Gimpshop, but for most elementary classrooms that would be primarily a teacher tool.
I am looking for tools that would be especially good to use with elementary students. What other great classroom tools should I share with them?