Notifications for new/changed stuff?

One of the usability issues that's been raised (thanks Ruth) is that currently you have to go actively looking to see if anything new has been added, e.g. if someone has left a comment on a blog.

Today explored the system's ability to do this. It turns out we can set up notification emails for changes to content, addition of new items… all sorts of stuff. Details
here . Have now done the set-up bit, as far as I can tell just now, so hopefully I'll get a notification when I post this blog…. Once it's working I'll post details of how to set it up.