A teacher at one of the schools I work for asked if, instead of having students send them files that are to be printed off in colour -- given that students aren't allowed to use the colour printer but staff can -- would it be possible to add the colour printer on the student's laptops, but require the teacher to authenticate for every print job.
Having done some googling, it isn't obviously possible, but it isn't clear that it is impossible, either. The computers in question are running Mac OS X 10.5, which uses CUPS.