Where I would appreciate advice is on a good strategy for displaying user-generated data back to the users, so that additional comments and interactions can be achieved.
I think a good strategy would be to copy the most successful social sites like Facebook, Twitter, Flickr, etc: when logging in they make sure you always have fresh content to look at either by showing data that they have expressly chosen to view (like contacts' activity or Facebook's Timeline), or by pushing similar/sponsored content (like Tw).
Alternatively you could show the user's most recent activity, but that works only if the user is already active.
Are there any other examples or approaches of collaborative web-maps out there that illustrate good ways of doing this?
Warning: shameless plug ahead.
For the last year I've been working on a project where users are allowed to tag, comment and star features server over WMS/WFS. They are not allowed to create/edit features (because I chose so).
The architecture is not very complicated (at least in theory):
- the app fetches the capabilities document of a WMS server (currently Geoserver)
- layers found in the document are added to the map and the user can toggle them at will
- the app will activate tags, comments and stars on layers whose features have an ID attribute
- these 'social' metatadata are stored on a separate postgresql server
- users can select a tag in the tag cloud and be shown features with that tag (see img below, notice the ugly green dots on Illinois, Michigan and Indiana)
I have not had time to work on the Timeline features that I mentioned in the previous para, but I intend to start working on them asap.
I can elaborate if you want, just let me know in the comments.