This is a feature request/suggestion
On my wish list is to have greater integration of tagging working across core modules and ability to search tags and get results across modules. It would be especially helpful if Forum posts could be tagged, at least by a moderator. Tagging on database entries and wiki pages would also be welcome.
Our company Knowledge in the Public Interest employs moodle for communities of practice for a variety of clients. The needs for tagging such as on delicious and diig are increasingly being asked for by members of our team who have task of extracting knowledge from the sites. Information about our company is available at http://kpublic.com
We currently have 5 moodle installations running and find it meets it a good 90% of our needs given it's remarkable suite of modules and administration interface. Thanks, Laren