Add a generic notes field for a user.
Or rather than in a user field, how about a user field for a particular course? I'd like to be able to add notes about a particular student in a course as instructor for my own use.
Correcting the version and the component.
N Hansen, one solution that might work could be to use a hidden Offline Assignment on the course: it gives you a comment box for each student, which won't be shown to the students (haven't checked, but as a hidden one it shouldn't, at least).
Fixed by Andrei (Google summer of code project) see MDL-10181