Hey there, I plugged a moodle web service client into the situation-centered Topicmaps UI DeepaMehta 4.
Despite its massive limitations functionality-wise I would like to know what you think about that and the idea to continue to develop it as an alternate UI for Moodle.
You can find the source code, some details on the application model and the documentation of our research questions in the wiki at http://docs.moodle.org/dev/TopicmapsWithMoodle
In short, what this DeepaMehta 4 plugin adds to moodle is mapping, free-form tagging, rating and association of materials in one big topical network spanning across courses.
If you're interested in setting up a pilot user study in your faculty or school please do not hesitate to get in touch with me, I will be glad if I can help you to get up and running with it.