The instructor I'm doing technical assistance for really wants the students to do a webbing diagram for the next course (actually it's more of a big collaborative flowchart) that multiple people can add boxes, text and lines to.
Does anybody have a suggestion for accomplishing this other than developing something in Flash (which I really don't know enough Flash to do).
If you don't mind using something outside of Moodle, Ithink Cmap might be exactly what you are looking for. We used it all last year and loved it. The software is free and you can set it up on your own server or use free public servers, most of which are university servers. I have the link to the download for an individual computer if you chose to use the public server: http://cmap.ihmc.us/download/index.php . If you look around the site, you will also find the download for the server software.
If you want to take a look at how we put it to use, go to one of my student's portfoio page at http://snipurl.com/Timz_Portfolio. THat page was created with Cmap and it running from a public Cmap server. Take some of the links at the bottoms of the boxes and you will see his concept maps created with Cmap for each of his subjects and units. These look more like typical concept maps than his main portfolio page.
The added benefit of the Cmaps on public servers is that the students can collaorate on the concept maps synchronously or assynchronously. If two or more students are on the same concept map, a text messaging window opens automatically to allow them to communicate with each other. It is really funny to see people's concept boxes moving around while you are working in your own area of the same concept map. LOL. For assynchrnous communication, the students can leave notes or attach forums to specific nodes. It is a really neat tool with a really neat history (used by meterological scientists and if you browse through the server you will even find real NASA Cmaps too).
Online mind mapping with the option to export to common formats.
You can also share the mind map but it dosen't yet support real time colaboration.
you could also search for Mind Meister which allows collaborative mind maps.
Hope these give you some ideas.
I have also found that mind42 works well for collaborative mind maps. I have used this recently to sum up a text together with university students.