A gem of a tool for English teachers: Marginalia forum web annotation tool for Moodle 1.9 and Moodle 2.0.

Marginalia
Add web annotation to your Moodle forums! This is a great pedagogical tool, from 2008, for those of you teaching English. You can use the Marginalia Moodle plugin to type corrections to your students' forum posts.

Here's a Youtube video showing you the plugin in action. No audio, so don't bother turning up the volume knob on your speakers.

I discovered this tool when I was surfing to find if there was something that I could use that was even close to UK Open University''s web annotation system in their Moodle 2.0. Boy was I glad to find this gem from 2008.